How to recover email accounts in mailbox

I have several email accounts which are all listed in my mailbox. for some reason I've ben asked to renter passwords for two of them but don't the password. when i go into settings for email accounts i don't have a option to say "forgot password" so unable to log into these emails.

Im able to log into email if I visit the individual email browsers.

Please advise how I can reset email passwords on mailbox.

Thank you