decouple from Proton account authentication

[kthomas-1]

I have a SL Premium subscription, but the authentication for SL currently uses my Proton account for authentication. Is it possible to decouple this from my Proton account and login with different credentials?

[kthomas-1]

Disregard. I see the option is right there under Settings. I can't believe I didn't notice it before.

[strawrhu]

Same question. Only...that option in settings just says "Unlink account" [with Proton]. The problem is, it took creating a SL Premium subscription with a link to a paid ProtonMail subscription to get the SL Premium tier without an additional charge. Will decoupling SL and PM after signing up for SL allow for the retention of the information that I am a paid PM subscriber (and therefore, qualified for the SL Premium tier)? Or will it now result in a bill for SL Premium? I would just like to secure my accounts with completely unique login credentials for the two services rather than using a single sign-on approach and re-using the credentials of my secure email account for SL.