Can monday.com OAuth work without giving a redirect_uri?

I found this piece of code in the Github Example app -

I have manually added the redirect_uri here, earlier it was not there.

Here is the corresponding GithubAuthManager -

This one had the redirect_uri from before.

Without the redirect_uri on mondayAuthManager, i was not getting redirected back to the backtourl, but when i added it, i was successfully redirected.

So why was there no redirect_uri in the out-of-the box code, am I missing something?