Have you tried accepting the "Invite link" from the postman to join the team, but it did not allow you to log in hence you tried clicking on "Trouble signing in" but that did not send you the reset email?
Probably it is because you do not have a Postman account. Please click on "Create account", provide the email id, unique username, and password and once the account is created you can click on the "Invite link" which should help you join the team.
If you still have issues logging in or joining the team, please reach out to us at help@postman.com.