Example

var layerWMTS = new ol.layer.GeoportalWMTS({
     layer  : "ORTHOIMAGERY.ORTHOPHOTOS"
});
layerWMTS.getLegends();
layerWMTS.getMetadata();
layerWMTS.getTitle();
layerWMTS.getDescription();
layerWMTS.getQuicklookUrl();
layerWMTS.getOriginators();

// Ex. configuration object for WMTS Layer
{
"name" : "GEOGRAPHICALGRIDSYSTEMS.MAPS.OVERVIEW",
"globalConstraint" : {
    "maxScaleDenominator" : 279541132.01435894,
    "minScaleDenominator" : 2183915.0938621787,
    "bbox" : {
        "left" : -179.5,
        "right" : 179.5,
        "top" : 75,
        "bottom" : -75
    }
},
"params" : {
    "url" : "https:*data.geopf.fr/wmts",
    "styles" : "normal",
    "version" : "1.0.0",
    "format" : "image/jpeg",
    "projection" : "EPSG:3857",
    "minScale" : 2183915.0938621787,
    "maxScale" : 279541132.01435894,
    "extent" : {
        "left" : -179.5,
        "right" : 179.5,
        "top" : 75,
        "bottom" : -75
    },
    "legends" : [
        {
            "format" : "image/jpeg",
            "url" : "https:*data.geopf.fr/annexes/ressources/legendes/LEGEND.jpg",
            "minScaleDenominator" : "200"
        }
    ],
    "title" : "Carte Mondiale pour la mini-vue",
    "description" : "Carte Mondiale pour la mini-vue",
    "tileMatrixSetLimits" : {
        "1" : {
            "minTileRow" : "0",
            "maxTileRow" : "1",
            "minTileCol" : "0",
            "maxTileCol" : "1"
        },
        "2" : {
            "minTileRow" : "0",
            "maxTileRow" : "3",
            "minTileCol" : "0",
            "maxTileCol" : "3"
        },
        "3" : {
            "minTileRow" : "1",
            "maxTileRow" : "6",
            "minTileCol" : "0",
            "maxTileCol" : "7"
        },
        "4" : {
            "minTileRow" : "2",
            "maxTileRow" : "13",
            "minTileCol" : "0",
            "maxTileCol" : "15"
        },
        "5" : {
            "minTileRow" : "5",
            "maxTileRow" : "26",
            "minTileCol" : "0",
            "maxTileCol" : "31"
        },
        "6" : {
            "minTileRow" : "11",
            "maxTileRow" : "52",
            "minTileCol" : "0",
            "maxTileCol" : "63"
        },
        "7" : {
            "minTileRow" : "22",
            "maxTileRow" : "105",
            "minTileCol" : "0",
            "maxTileCol" : "127"
        },
        "8" : {
            "minTileRow" : "45",
            "maxTileRow" : "210",
            "minTileCol" : "0",
            "maxTileCol" : "255"
        }
    },
    "TMSLink" : "PM_1_8",
    "matrixIds" : [
        "1",
        "2",
        "3",
        "4",
        "5",
        "6",
        "7",
        "8"
    ],
    "tileMatrices" : {
        "1" : {
            "matrixId" : "1",
            "matrixHeight" : 2,
            "matrixWidth" : 2,
            "scaleDenominator" : 279541132.01435894,
            "tileHeight" : 256,
            "tileWidth" : 256,
            "topLeftCorner" : {
                "x" : -20037508.3427892,
                "y" : 20037508.3427892
            }
        },
        "2" : {
            "matrixId" : "2",
            "matrixHeight" : 4,
            "matrixWidth" : 4,
            "scaleDenominator" : 139770566.0071793,
            "tileHeight" : 256,
            "tileWidth" : 256,
            "topLeftCorner" : {
                "x" : -20037508.3427892,
                "y" : 20037508.3427892
            }
        },
        "3" : {
            "matrixId" : "3",
            "matrixHeight" : 8,
            "matrixWidth" : 8,
            "scaleDenominator" : 69885283.00358965,
            "tileHeight" : 256,
            "tileWidth" : 256,
            "topLeftCorner" : {
                "x" : -20037508.3427892,
                "y" : 20037508.3427892
            }
        },
        "4" : {
            "matrixId" : "4",
            "matrixHeight" : 16,
            "matrixWidth" : 16,
            "scaleDenominator" : 34942641.50179486,
            "tileHeight" : 256,
            "tileWidth" : 256,
            "topLeftCorner" : {
                "x" : -20037508.3427892,
                "y" : 20037508.3427892
            }
        },
        "5" : {
            "matrixId" : "5",
            "matrixHeight" : 32,
            "matrixWidth" : 32,
            "scaleDenominator" : 17471320.75089743,
            "tileHeight" : 256,
            "tileWidth" : 256,
            "topLeftCorner" : {
                "x" : -20037508.3427892,
                "y" : 20037508.3427892
            }
        },
        "6" : {
            "matrixId" : "6",
            "matrixHeight" : 64,
            "matrixWidth" : 64,
            "scaleDenominator" : 8735660.375448715,
            "tileHeight" : 256,
            "tileWidth" : 256,
            "topLeftCorner" : {
                "x" : -20037508.3427892,
                "y" : 20037508.3427892
            }
        },
        "7" : {
            "matrixId" : "7",
            "matrixHeight" : 128,
            "matrixWidth" : 128,
            "scaleDenominator" : 4367830.1877243575,
            "tileHeight" : 256,
            "tileWidth" : 256,
            "topLeftCorner" : {
                "x" : -20037508.3427892,
                "y" : 20037508.3427892
            }
        },
        "8" : {
            "matrixId" : "8",
            "matrixHeight" : 256,
            "matrixWidth" : 256,
            "scaleDenominator" : 2183915.0938621787,
            "tileHeight" : 256,
            "tileWidth" : 256,
            "topLeftCorner" : {
                "x" : -20037508.3427892,
                "y" : 20037508.3427892
            }
        }
    },
    "nativeResolutions" : [
        "78271.51696402048",
        "39135.75848201023",
        "19567.87924100512",
        "9783.939620502561",
        "4891.969810251280",
        "2445.984905125640",
        "1222.992452562820",
        "611.4962262814100"
    ]
}