Braintree Gateway

I’m trying to get started with the braintree gateway but without successful.
I run on self host version 4.2.2, I have put the credentials and in the test mode I have the following message .

Braintree\Exception\Authentication - It may help to set new passwords or generate new API keys.

If I give it to normal mode it will stick to the moment when I click on the payment button.

Credentials are definitely right …

There is something I still have to do ??


I’m not sure, the only explanations I’ve seen for the error are either invalid credentials or incorrectly enabling/disabling test mode.