Cesium OpenStreetMapImageryProvider URL gives, ERROR: 418 I'm a teapot


I am using below snippet to show openstreetmap layer in poc app, but i am getting http ERROR: 418 I’m a teapot , please assist in this, refer below code.

new Cesium.OpenStreetMapImageryProvider({
url: ‘https://a.tile.openstreetmap.org/’,

HTTP 418 errors are likely an intentional response due to not following the Tile Usage Policy.

The correct URL is https://tile.openstreetmap.org/ the a, b and c subdomains have been obsolete for quite a while now.