From the official RSL discord known-bugs
You may be stumbling upon an issue where you cannot log into the game, similar to the screenshot attached.
The issue is reported and looked into..
Please try a VPN and see if that will solve your issues, if that should not do the trick open a support ticket please until the issue is fixed (no ETA on that): https://plarium.com/en/support/
Update 2.0: Please clear the cache from your Google Play Store, update WebView and other google related apps and see, if that will do the trick (it worked for some people already).
Same problem as Zarya, works on mobile but does not work since yet another update on Plarium...along with booting my Hell Hades artifact enhancer version out again! can you please remedy the Plarium version on PC and keep the "updates" to a minimum. Playing on mobile is rubbish in comparison.