TL;DR: When you try to login with PTC (pokemon trainer center), in the webview click menu and open with Firefox. thats about it!!
Ok so while opening the Webview link in my chrome(and chromium) I saw that it's throwing error that CSRF token not found in session cookie, and that it's using ORY Hydra. I have used ORY hydra in one of the orgs where I used to work, it's a very popular open source OAuth solution. But this particular issue used to happen in Chrome due to the SameSite=None behavior change.
Github link for some context and further research: https://github.com/ory/hydra/issues/1988#issuecomment-673937567
Anyway, after the login it deeplinks into the pokemongo app through a pokemongo:// protocol. So I mean you can technically login in any device , and use adb to open the intent as well. But, using firefox is possibly the easiest solution instead of chrome.
by legndery