Error when start demo app

When I init the demo app using the React UI Kit, I am receiving in DevTool Console this error:

Uncaught ReferenceError: Buffer is not defined
at node_modules/ws/lib/constants.js (constants.js:5)
at __require2 (chunk-F5R5HRHB.js?v=4afefd13:19)
at node_modules/ws/lib/buffer-util.js (buffer-util.js:3)
at __require2 (chunk-F5R5HRHB.js?v=4afefd13:19)
at node_modules/ws/lib/permessage-deflate.js (permessage-deflate.js:5)
at __require2 (chunk-F5R5HRHB.js?v=4afefd13:19)
at node_modules/ws/lib/websocket.js (websocket.js:14)
at __require2 (chunk-F5R5HRHB.js?v=4afefd13:19)
at node_modules/ws/index.js (index.js:3)
at __require2 (chunk-F5R5HRHB.js?v=4afefd13:19)
This happens when I add the SendBirdProvider or something related with the UI Kit.

The last time I did a example, was on the last friday, but today is not working. I tried with different projects, even in differents laptop. Besides, I have installed the last version of Node (v15) and NPM(v7) and keeps failing.

What could be the problem?

Best