You'll notice that if your SAML SSO enabled team does not have an "Invitations" section to email members invitations to your team, this is due to your team being SAML SSO enabled.
To invite new members to your team, you can construct a team name based on your team slug. The team slug name can be found on the URL used to access your Honeycomb team.
https://ui.honeycomb.io/join_team/<team_slug>
Once a user has requested access to the team, Team Owners will need to approve the request (via email) to complete their registration.