The Primary Password is only used locally to encrypt the logins stored in the profile folder (logins.json) and are shown in the Password Manager (about:logins page). This is different than the password you use to connect to the Sync account if that is what you were doing.

• https://support.mozilla.org/en-US/kb/use-primary-password-protect-stored-logins

If you fail to remember the password, you can reset it. If you do that, you will lose your logins so I suggest that you export them first. You will run foul of a bug when you want to import them later but there is a fix for that, mentioned in comments in the bug report and in a Reddit thread. You also need to change the following preference in about:config to true. signon.management.page.fileImport.enabled

https://support.mozilla.org/en-US/kb/export-login-data-firefox https://support.mozilla.org/en-US/kb/reset-your-primary-password-if-youve-forgotten-it https://bugzilla.mozilla.org/show_bug.cgi?id=1781213 https://support.mozilla.org/en-US/kb/about-config-editor-firefox