While working with different delivery methods in Odoo, If you get any issue first check following configuration.
- Check your delivery method credential
- Check your packaging methods
- Check your Delivery Service Type
- Published on Website or not
- Production/Test Env
- Your warehouse company address (with all proper detail including phone number)
- Check product weight
- Customer Address (Shipping Address)
- Address State code are valid or not.
After checking all and if you still don't get any Delivery methods on checkout page the simple way to checking is go to backend and create Quotation with same product and customer address and check the error.
After all cases if you face still any error then simply google delivery method name + test site and enter same detail in test site if its not succeed then contact to your delivery provider for further assistance.
Hope it helps. :)