Hi!

I'm trying to GET invoices by contact id and a custom field.

Let's say I have a custom field with label 'userId', and I want to search for an invoice that it's userId == 2.
What's the correct URL to GET in my request?
right now I'm trying without success:

https://invoice.zoho.com/api/v3/invoices?customer_id=<contactId>&custom_field=userId=2

Thanks a lot!