When we see this error 'Need admin approval':
If we look at the help guide we mention this in the notes:
The integration requires an Entra ID admin to have the same email in Entra ID and in Bob as well. Thus, the Entra ID admin should enter Bob by using his Entra ID email (meaning the Work email in Bob should be the same as the Entra ID email).
Please note: Once the integration is configured, removing the user in Bob with the same email as the Entra ID admin will not affect the integration.