On Step 5 it states: Enter the Username of the individual or team account you want to transfer to.

[Nilesh Patel]

This question is in reference to Atlassian Documentation: Change or transfer repository ownership

How does one transfer ownership to a team if the we cannot associate a team with an email address?

[evzijst]

Not sure I follow. Just type the username of the team you want to transfer the repo to.

If your question is what happens after the transfer request has been sent, then all the admins get an email that allows them to accept the transfer into the team.