Error when attempting to add an item to a related list in Contacts

Error when attempting to add an item to a related list in Contacts

Hi,  In our contacts layout we have created a Lookup field called "Trusted" to allow users to link other contacts to main contact.  I need to add items to this list for any given contact via the REST API.  I've been following the article but I'm getting an error and I cannot figure out what's wrong.

Here's the (abbreviated) results of getting the metadata information for Contacts based on the article.  Note the "Trusted" field we added to contacts is shown.

GET {{api-domain}}/crm/v2/settings/related_lists?module=Contacts
    "related_lists": [
            "sequence_number": "35",
            "display_label": "Trusted",
            "api_name": "Trusted",
            "module": "Contacts",
            "name": "Trusted",
            "action": null,
            "id": "5027237000000392183",
            "href": "Contacts/{ENTITYID}/Trusted",
            "type": "custom_lookup"
I created a test contact and added some trusted contacts to that via the web UI, and I can retrieve that with no issues as shown in the article via GET {{api-domain}}/crm/v2/Contacts/5027237000001319012/Trusted where 5027237000001319012 is the ID of the test record in my sandbox.

Now, when I attempt to add another trusted contact (5027237000002017001) to my test contact (5027237000001319012) via the REST API, I use the following call:
PUT {{api-domain}}/crm/v2/Contacts/5027237000001319012/Trusted/5027237000002017001
Body = {
    "data": [

However, I get a 400 bad request HTTP status code with the following body:
    "code": "INVALID_DATA",
    "details": {},
    "message": "the module name given seems to be invalid",
    "status": "error"

What am I doing wrong?  

    Zoho Developer Community

                              Zoho Desk Resources

                              • Desk Community Learning Series

                              • Digest

                              • Functions

                              • Meetups

                              • Kbase

                              • Resources

                              • Glossary

                              • Desk Marketplace

                              • MVP Corner

                              • Word of the Day

                                  Zoho Marketing Automation

                                          Manage your brands on social media

                                                Zoho TeamInbox Resources

                                                  Zoho DataPrep Resources

                                                    Zoho CRM Plus Resources

                                                      Zoho Books Resources

                                                        Zoho Subscriptions Resources

                                                          Zoho Projects Resources

                                                            Zoho Sprints Resources

                                                              Qntrl Resources

                                                                Zoho Creator Resources

                                                                  Zoho WorkDrive Resources

                                                                    Zoho Campaigns Resources

                                                                      Zoho CRM Resources

                                                                      • CRM Community Learning Series

                                                                        CRM Community Learning Series

                                                                      • Tips


                                                                      • Functions


                                                                      • Meetups


                                                                      • Kbase


                                                                      • Resources


                                                                      • Digest


                                                                      • CRM Marketplace

                                                                        CRM Marketplace

                                                                      • MVP Corner

                                                                        MVP Corner



                                                                          Design. Discuss. Deliver.

                                                                          Create visually engaging stories with Zoho Show.

                                                                          Get Started Now