How administrator recover password if he is the only admin and Self Service Recover not configured

Hello murilourban, I'm not sure if you've received assistance with this. 

Due to the nature of this request and to ensure the safety and security, I'd highly recommend reaching out to your Technical Account Manager or Business Account Manager (if you have one). Depending on the scale of your environment, it will require assistance from various teams. 

I'm not sure what type of administrator role you're referencing but, if you have a Global Administrator within your Azure environment. They have the ability to reset the password for any user in Azure. 

Here is a document referencing the roles assigned to a Global Admin: https://docs.microsoft.com/en-us/azure/active-directory/users-groups-roles/directory-assign-admin-roles#company-administrator-permissions

Also, going forward I'd highly recommend ensuring you do not have a single point of failure regarding administrator access. It may be a matter of assigning particular roles based off a containerized system which will increase cross-team communication/ coordination and limit one individual from having full-scope access to your entire environment.

Please review the following documentation regarding Azure Access Control and information regarding RBAC, User Account types and best practices. 
https://docs.microsoft.com/en-us/azure/role-based-access-control/rbac-and-directory-admin-roles
https://docs.microsoft.com/en-us/azure/security/fundamentals/identity-management-best-practices