Hi @Cinthia Rodriguez ,
as far as I know you can just delete the user in Microsoft 365 admin center even if a license is assigned to the user.
The license will be available in the license pool after the user is delete.
If you delete the user in PowerShell or any other way the license might be still assigned to the deleted user and you have to unassign the license manually.
(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)
Regards
Andreas Baumgarten