public class MyServiceRequestData
{
     public string DisplayNameEn { get; set; }
     public string DisplayNameFr { get; set; }
     public string DataFieldA { get; set; }
}  

const int userId = 100;
const int serviceRequestId = 100;
// Provide some metadata that helps to describe this particular service request.
var metadata = new { MetaDataFieldA = "test" };
     
// Retrieve the service request document.
//This function accepets a generic parameter, it's not limited to MyServiceRequestData
const int serviceRequestId = 100;
var serviceRequest = await documentManager.Get<MyServiceRequestData>(serviceRequestId);

// Update the service request document with some new data.
serviceRequest.DataFieldA = "Test 123";

// Update the service request document.
await _documentManager.Update(serviceRequest, metadata, serviceRequest.DisplayNameEn, serviceRequest.DisplayNameFr, "1.1", serviceRequestId, userId);