I need help with setting up a 2Checkout gateway

My Environment: Joomla and CB Subs are up to date:
Szenario:
I tried to set up a gateway for my 2Checkout Gateway (Sandbox) account...I followed accurately the CB Subs Manual. But when I tried to do a (test)payment, the following window appeared:



so my questions are:
1) ....did I use the wrong user? In the admin area of 2Checkout I created a user with API Access and API update rights...is this correct?
2) The field 2Checkout Company info from API (in the Gateway for 2Checkout) always prompts the message: "Error: 2checkout: API acct/detail_company_info fetch error: error status: 401" ...but I used the correct username and pwd???!!!???

..any idea?

regards

The error code PE102 appears to be related to the account not being completely activated or you've a configuration problem. See the below regarding that error code.

help.2checkout.com/articles/Knowledge_Article/Error-Code-PE102

When supplying values to the parameters ensure there are no leading or trailing spaces as sometimes that can be the issue, but sounds like your account just hasn't been approved to sell yet.

Concerning this issue I got a useful feedback from the 2checkout customer service:

As you see the URL attached to the error window is as follows:

www.2checkout.com/checkout/purchase



...but because I created a 2Checkout-Demo-gateway (in the CBSubs Backend) the customer service told me that this URL should be as follows:

sandbox.2checkout.com/checkout/purchase

...so I am very sure this is the problem....could you verify this?

regards

Ensure you've "2Checkout Demo/Test-mode" set to "Test Demo mode" when using sandbox.

..it is definitely set to 'TEST Demo Mode'