Paypal Express: test payments

[cole007]

Have set up a checkout using Paypal Express using the instructions outlined.
However when attempt to check out with the paypal button loaded into the template I get the following response when in Test Mode:

Security header is not valid

This happens irrespective of whether method is set to Mark or Sole/solo (and also both login and billing). Is this expected behaviour?

[cole007]

By means of update it looks like the issue was using the credentials as set out in the plugin instructions.

The solution (for test payments) was registering a developer account at https://developer.paypal.com/ and then go to Sandbox > Accounts.

You will need a Business Account (if none Create one) and where shown click on Manage Account > View/edit account. In the modal click on the API credentials tab and use the details under NVP/SOAP Sandbox API Credentials

[kaspar-allenbach]

If you have test mode enabled but have your live PayPal credentials set. Then you get this error.

[yoannisj]

I am getting this error in "live" mode, with my merchant account's credentials (username, client Id and secret).

The instructions in this plugin's readme file are outdated, as the paypal UI seems to have changed. In test mode it works, with the credentials for the sandbox business account found here: https://developer.paypal.com/developer/accounts/

It is unclear which credentials should be used in live mode. I tried the following two credentials, but both gave me the Security header is not valid error when clicking on the Paypal express button:

1. The merchant account email, and client id and secret found here:

• log into the merchant account
• go to https://www.paypal.com/commercesetup/APICredentials?guided=true

2. The NVP/SOAP credentials found here:

• log into the merchant account
• go to https://developer.paypal.com/developer/applications
• switch the "live" tab on
• click on the "manage webhooks" button
• switch the "live" tab on again

Are there any settings / features to turn on on the merchant account to get the Paypal Express gateway to work? Where can I find the live credentials for Paypal Express in Paypal's current merchant account UI/dashboard?

[yoannisj]

I also found this guide for Paypal Express, but it is very vague: "https://developer.paypal.com/docs/archive/express-checkout/integration-guide/ECGoingLive/. If anyone has more information, that would be most welcome so this plugin's readme file can be updated accordingly.