How to handle Newtonsoft.Json.JsonReaderException expecting JSON receiving HTML

I am receiving an error when calling an API and it returns HTML(error occured) instead of JSON which causes the Xamarin app to crash. I realize this is not ideal for the API to return this, but what I am working with.

Newtonsoft.Json.JsonReaderException: Unexpected character encountered while parsing value: <. Path '', line 0, position 0.

Task<ApiResponse> GetContentModel();