I would like to update the attribute via API. Could you please give an example?


You can update the customer attributes via Restful APIs, here is the guide: API Support 

Regarding the "updating value of customer attributes",  please take a look at this

"custom_attributes": [


            "attribute_code": "ca_document_type",

            "value": "217"



Hope this information will help you.

If you have any queries, please feel free to contact us.

We're more than happy to support you.