A short article with tips how you can find gMSA accounts in Active Directory or AD.
First off, import the module
ActiveDirectory.
Then you can run the following snippet to find some gMsa accounts of which you know part of the name of.
Import-Module ActiveDirectory
Get-ADObject -Filter {ObjectClass -eq "msDS-GroupManagedServiceAccount" -and Name -Like '*SomeGmsa*' } -Properties DistinguishedName, SamAccountName | Select DistinguishedName, SamAccountName
This yields the results:
DistinguishedName SamAccountName
----------------- --------------
CN=gMSA1DVSomeGmsa,CN=Managed Service Accounts,DC=someacme,DC=org MSA1DVSomeAcmeP$
CN=gMSA1_gMSA1DGmsaPT,CN=Managed Service Accounts,DC=someacme,DC=org MSA1gMSA1DVSomeAcme$
CN=gMSA1_DVSomeGmsaPT,CN=Managed Service Accounts,DC=someacme,DC=org MSA1DVSomeAcmePT$
You can search for gMSA users in AD like this:
Import-Module ActiveDirectory
Get-ADServiceAccount -Filter "Name -like '*SomeGmsa*'"
This should yield a list of matching gMSA users with given name :

You can also ask for all properties of Gmsa users using -Properties with * :
Import-Module ActiveDirectory
Get-ADObject -Filter {ObjectClass -eq "msDS-GroupManagedServiceAccount" -and Name -Like '*SomeGmsa*' } -Properties *

Please note that your server should also install the gMsa account where it shall be used ! And to use the module
ActiveDirectory, the Windows feature must be installed.
From Powershell admin console you can run:
# Remember to install the RSAT-AD-Powershell module
Add-WindowsFeature RSAT-AD-PowerShell
Install-ADServiceAccount SomeGmsa$
Import-Module ActiveDirectory
Get-ADObject -Filter {ObjectClass -eq "msDS-GroupManagedServiceAccount" -and Name -Like '*SomeGmsa*' } -Properties DistinguishedName, SamAccountName | Select DistinguishedName, SamAccountName
Note that you gMsa user has a SamAccountName which is suffixed by '$'. This can be set up in IIS for you application as the app pool identity. The username will be in this example:
MYDOMAIN\SomeGmsa$
The password of the gMSa service account will actually be empty ! Instead, the service account is installed as shown above using the cmd-let
Install-AdServiceAccount.