Where and how to get POP3 emails off Samsung Phone?

I recently did a backup of my email account using the Samsung Email app on my mobile phone (Galaxy A31 model SM-A315F), as it was set up as a POP3 account, then I changed it to an IMAP account, but all the POP3 emails did not back up and restore. Is it still anywhere on the phone? Where and how can I retrieve it?