Hello @Krupa Gundraju (Larsen & Toubro Infotech Limit) and thanks for reaching out. To invoke the Update mobileDeviceManagementPolicy operation you will need to provide the id of a mobilityManagementPolicy object or resource. You can list available ones using the List mobileDeviceManagementPolicies operation.
You can retrieve a list of policies using MS Graph PowerShell use the following script:
Select-MgProfile -Name "beta"
Connect-MgGraph -Scopes Policy.Read.All
Get-MgPolicyMobileDeviceManagementPolicy
And update one passing the id property value as the MobilityManagementPolicyId
param:
Select-MgProfile -Name "beta"
Connect-MgGraph -Scopes Policy.ReadWrite.MobilityManagement
Update-MgPolicyMobileDeviceManagementPolicy -MobilityManagementPolicyId {id} # follows additional parameters
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