Thank you Wearsky,
I was able to easily find it by creating a test user with only that license assigned.
Then run the Graph Powershell command to get service plans for that test user:
Connect-Graph -Scopes User.ReadWrite.All, Organization.Read.All
Get-MgUserLicenseDetail -UserId "<user sign-in name (UPN)>"
(Get-MgUserLicenseDetail -UserId <user sign-in name (UPN)> -Property ServicePlans).ServicePlans
I found that there were 7 service plans for the PowerApps Premium license.
The Dynamic Query only needed one of them.
I was then able to validate by testing different users against the query.
Denise