Problem with CORS on a remote server, although locally everything is ok. What's the matter?

Question

proxy

The react application connects through the cctx library to exchange resources.
I run it locally - it gives a CORS error . I
set the Proxy parameter for the object -

const exchangeObj = new ccxt[exchangeId] (params)
if (proxy) exchangeObj.proxy = 'https://thingproxy.freeboard.io/fetch/'

Locally everything works without problems.

I'm building an application, uploading it to the server on beget - the error "Failed to load resource: the server responded with a status of 401 ()"

Although I repeat locally, everything works fine. Is it possible to somehow get to the bottom of the causes and fix them?

Thank you in advance