Yes, you can use the New-MgRoleManagementDirectoryRoleAssignmentScheduleRequest cmdlet for that, or the underlying call to the /roleManagement/directory/roleAssignmentScheduleRequests Graph API endpoint. For your scenario, the selfActivate action should do.
Yoi can find additional details in the documentation: https://video2.skills-academy.com/en-us/graph/api/rbacapplication-post-roleassignmentschedulerequests?view=graph-rest-1.0&tabs=powershell