I've created a Powershell-connector and you can't believe what happened next

I'm trying to get all users from an API through Invoke-RestMethod, and have created the definition file and created the sync project. When clicking on User (All) the script gets all users from the API but I can't figure out how the logic works (or doesn't work) when I want to view just one object.

I've created to custom commands in the xml, Get-ACMEUsers and Get-ACMEUser. The both take four parameters for the actual connection, and Get-ACMEUser have an additional parameter for defining the actual user to get.

What I don't understand is how to get the command to take the actual object that I click on when I browse and get that as a parameter on the Get-ACMEUser command. If I specify which user to get with the fixed value parameter it works, but it shows the same user independent of which user I click on to view.

My custom command wants a user name in a string, and I'm limited to String, Int, DateTime and Bool. I can't "send" the entire object.

<ReadConfiguration>
	<ListingCommand Command="Get-ACMEUsers">
		<SetParameter Param="Domain" Source="GlobalVariable" Value="_domain" />
		<SetParameter Param="RestUri" Source="GlobalVariable" Value="_restUri" />
		<SetParameter Param="CertificateThumbprint" Source="GlobalVariable" Value="_certThumb" />
		<SetParameter Param="APIkey" Source="GlobalVariable" Value="_apiKey" />
	</ListingCommand>
	<CommandSequence>
		<Item Command="Get-ACMEUser" Order="1" >
			<SetParameter Param="Domain" Source="GlobalVariable" Value="_domain" />
			<SetParameter Param="RestUri" Source="GlobalVariable" Value="_restUri" />
			<SetParameter Param="CertificateThumbprint" Source="GlobalVariable" Value="_certThumb" />
			<SetParameter Param="APIkey" Source="GlobalVariable" Value="_apiKey" />
			<SetParameter Param="Id" Source="FixedValue" Value="joedoe2020" />
		</Item>
	</CommandSequence>
</ReadConfiguration>

Also, I have two attributes returned from the API that according to Powershell are String but I get an error when the connector is trying to map the two attributes.

This is the error message I get:

[1777160] Property (ValidFrom@User) could not read the value from system object (joedoe2020)!
[1777022] Schema property (ValidFrom@User) only accepts data of type (System.DateTime).
The value loaded (2020-11-27T10:30:20.149) is however type (System.String).

Any help is greatly appreciated!

PS. One Identity 8.1.3, Windows Server 2016, SQL Server 2016 CU15