Refit.ApiException: 'An error occured deserializing the response.'

[Akomspatrick]

I want to use refit to generate an sdk but am getting the error => : The JSON value could not be converted to LanguageExt.Either`2

this is my controller
[HttpGet(template: DocumentVersionManagerAPIEndPoints.Model.Get, Name =
DocumentVersionManagerAPIEndPoints.Model.Get)]
public Task Get(CancellationToken cToken) => _sender.Send(new GetAllModelQuery(), cToken).ToActionResult();

This is my refit interface
[Get("/api/v1/Models")]
Task<Either<GeneralFailure, ModelResponseDTO>> Get(CancellationToken cToken);
I also tried using [Get("/api/v1/Models")]
Task Get(CancellationToken cToken);

in both cases I got
An error occured deserializing the response.
Please I need help is there a way I can correctly have Either Result in my controller return type and still Use Refit for my SDK development ?