Activate your PIM role with Graph

function Activate-PIMRole {
   [CmdletBinding(SupportsShouldProcess)]

   # https://worktogether.tech/2023/01/07/enable-pim-role-thru-microsoft-graph-powershell/
   Write-Host "Activate one of your PIM roles"

   # Check if there is a existing connection to MgGraph
   if ((Get-MgContext) -eq $null) {
      $null = Connect-MGGraph -TenantId '<tenantId>' -ClientId '<clientId of your Graph application>' # Use $null to capture unwanted output
   }

   Install-Module -Name 'Microsoft.Graph.Identity.Governance' -RequiredVersion 2.19.0 -Scope AllUsers

   $context = Get-MgContext
   $currentUser = Get-MgUser -UserId $context.Account
   $currentUserId = $currentUser.Id
   $currentUserUPN = $currentUser.UserPrincipalName

   # Get all available roles
   # https://learn.microsoft.com/en-us/powershell/module/microsoft.graph.identity.governance/get-mgrolemanagementdirectoryroleeligibilityschedule?view=graph-powershell-1.0
   $myRoles = Get-MgRoleManagementDirectoryRoleEligibilitySchedule -ExpandProperty RoleDefinition -All -Filter "principalId eq '$currentuserId'"

   Write-Host "Your available roles are:"
   Write-Host ''

   $menu = @{}
   for ($i=0; $i -lt $myRoles.count; $i++) {
      Write-Host "$i. $($myRoles[$i].RoleDefinition.DisplayName)"
      $menu.Add($i,($myRoles[$i].RoleDefinition.DisplayName))
   }
   [int]$selectedRole = Read-Host "Enter number of role to activate"
   Write-Host ''

   # Setup parameters for activation
   $params = @{
      Action = "selfActivate"
      PrincipalId = $myRoles[$selectedRole].PrincipalId
      RoleDefinitionId = $myRoles[$selectedRole].RoleDefinitionId
      DirectoryScopeId = $myRoles[$selectedRole].DirectoryScopeId
      Justification = "Enable role for [$currentUserUPN] with script"
      ScheduleInfo = @{
         StartDateTime = Get-Date
         Expiration = @{
            Type = "AfterDuration"
            Duration = "PT4H"
         }
      }
      TicketInfo = @{
         TicketNumber = 'CHA111111'
         TicketSystem = 'ServiceManager'
      }
   }

   # Activate the role
   Write-Host "Activate role [$($myRoles[$selectedRole].RoleDefinition.DisplayName)]"
   try {
      $null = New-MgRoleManagementDirectoryRoleAssignmentScheduleRequest -BodyParameter $params
   }
   catch {
      Write-Host "...something went wrong with [New-MgRoleManagementDirectoryRoleAssignmentScheduleRequest - Activate]"
      Write-Host "`tERROR : $($_.Exception.message)"
   }
   Write-Host "...done"
   Write-Host ''

   # Wait until Role Assignment is activated
}

 # Wait until Role Assignment is activated
   Write-Host "...wait until Role Assignment [$($myRoles[$selectedRole].RoleDefinition.DisplayName)] is activated"
   do {
      Write-Host "...wait"
      Start-Sleep -Seconds 5
   } while ((((Get-MgRoleManagementDirectoryRoleAssignment -Filter "roleDefinitionId eq '$($myRoles[$selectedRole].RoleDefinitionId)'").PrincipalId) -eq $currentUserId) -eq $false)
   Write-Host "...done"
   Write-Host ''

Activate-PIMRole