Turn off Suggest Firefox Relay email masks to protect your email address in the Settings.

it was already -turned off and this notification still appears , i have two screenshots of this, if you need ..

Do you have the Relay add-on? Check your Extensions.

no, i dont have it. see my two screenshots , as you see this notification comes - the site of pc forums. in dutch above means- ? your accountnames for ?mailmaskers are switched off...i co teraz?

https://www.askvg.com/disable-or-remove-firefox-relay-service-in-firefox-browser/