How to update my email passwords on my iPhone 12 Pro?

Which was on my desk top computer. When I got this iPhone I added those existing emails to my phone. Then I remember seeing settings >>>mail, contacts, calendars. Now there was a no such thing. I just need to change the password in my iPhone for the email. I don’t want make a new password. Thanks

It doesn’t show any of my email accounts that are on my phone in my passwords section.

Weird that I can’t find that now they must of deleted it. And if you google it it says to setting>mail, contacts, etc.

Not sure what to do.

Thanks for answering.