How to use custom converters in calculated attributes?

Hi Community. 

I have a question regarding calculated attributes in freedomUI. 

Below is the mock of what I mean

"ActualModelAttribute": {
	"modelConfig": { 
		"path": "PDS.AttributeName"
	}
},
"CalculatedAttribute": {
	"from": "ActualModelAttribute",
	"converter": "usr.MyCustomConverter"
}

If I define my customConverter directly in page schema I get an error that the converter is not found in converterRegistry. Is there any way to add it?