I want to develop a custom shipping module for Odoo, but I can't find the documentation for it and all the shipping source is Enterprise, so I can't see it without paying.
I found the Odoo Developer guid here: https://www.odoo.com/documentation/13.0/
I found how to create a module: https://www.odoo.com/documentation/13.0/howtos/backend.html
I found the Guide for Payment processors: https://www.odoo.com/documentation/user/13.0/ecommerce/shopper_experience/payment.html
Where is the documentation for shipping connectors? I know it can be done, there are third party shipping connectors on the odoo marketplace.