Updating custom product fields through api

Hello,

First and foremost know that all your help is greatly appreciated.

I am trying to populate a product field with the date of the invoice on each line with zapier. It doesn’t seem like zapier is picking up the custom field, so I believe I may have to update the invoice with a custom request.

How would I update an invoice custom field? Do I call it by the name I’ve labeled it as, or by custom_field_1 or something?

Thank you thank you thank you!

Hi,

You can reference the fields using custom_value1 and custom_value2