Hello-

I've looked at and followed all of the above tutorials many times. The problem that I am running into is that once paypal redirects you back to your website, odoo generates a '500 internal server error.' The url in the address bar contains a bunch of details about the transaction (item, amount, etc).

When I do these steps in paypal sandbox, the money does get sent from 1 account to the other, odoo just never gets notified that the transaction has completed. I did check, and the IPN checkbox is checked on the payment acquirer. Any help will be appreciated! Thank you! 

Hi Zahin,

Please refer this link to integrate PayPal account with E-commerce https://www.odoo.com/documentation/user/10.0/ecommerce/shopper_experience/paypal.html

 If you need more about other Payment methods integration refer the below link

https://www.odoo.com/documentation/user/10.0/ecommerce.html
Hope this can help you

Hi

Refer below link may help you.

https://www.odoo.com/forum/help-1/question/credit-cards-overseas-transactions-paypal-in-odoo-52908

https://www.odoo.com/forum/help-1/question/open-source-ecommerce-eshop-integration-30932

https://www.odoo.com/forum/help-1/question/is-there-any-open-erp-module-which-integrates-authorized-net-payment-gate-way-33198