I am trying to use the REST API to update a custom field for a contact. I have looked up the database name from Admin->Settings (customField) and have read that there needs to be an underscore preceding the database name (customField). The data type for my field is text. Here is the request I am sending to PATCH "https://api.infusionsoft.com/crm/rest/v1/contacts/userId?accesstoken=access_token" (userID and access_token values replaced of course)
And here is the response I get from Infusionsoft:
message: 'Input value is invalid: _customField'
The docs seem to say that the content should be an object, but do not specify what that object should contain.
Are there errors in my request and how can I successfully update a contact custom field?