OAuth 1.1.15. Minecraft 1.20.1 with forge 47.2.1.6. I can't add an account because the page doesn't open in the browser.
Operating system: Linux Mint 21.2
Testing browser (change prefer browser on OS):
Google Chrome 120.0.6099.129 (64 bits)
Firefox Browser 121.0 (64 bits)
Yandex Browser 23.5.1.667 stable (64-bit)
In any case, Oauth is waiting for actions in the browser, but the page does not open.
I have an idea how to fix this minimally. Add the button "copy this link to paste into the browser manually" while waiting for actions.

Or so: before trying to open a page in a browser, write a link string in the minecraft log