Understand product licenses
A product license belongs to the signed-in actor, the application user who authorizes actions. It is separate from a connected mailbox. See identity concepts.
Administrators manage licenses in Account administration with the relevant permissions. MailGen and other product access are separate. A license alone does not authorize every operation.
Execution checks the current license and rights. A model grant cannot replace a MailGen license, mailbox ownership, or separate tool grant. If a licensed feature remains unavailable, check those independent requirements. See tool access.