Add WSM as basemap in 3.x

[ADITYAKUMAR1]

Hi,

  I want to add WMS layer as basemap layer. I am using the below code to add the same.

greylayer = "https://gis.ices.dk/gis/services/World_Topo_Map/MapServer/WMSServer?request=GetCapabilities&service=...";
var ltGreyLayer = new BasemapLayer({ url: greylayer });

var ltGreyBasemap = new Basemap({
layers: [ltGreyLayer],
id: 'ltGrey',
title: 'Light Grey',
thumbnailUrl: 'https://xx/arcgis/rest/services/Metropolis_basemap/MapServer/info/thumbnail'
});

config.basemaps.push(ltGreyBasemap);

On doing so I am getting the below error while loading the map.

Any idea how to fix it?

Thanks

Aditya