Asking for a help about PayPal checkout system

[TDS_HOSTING]

Hi everyone

I hope you are doing well. I would like you to support me understand or fix this issue that i am facing.

In fact, i would like to configure PayPal as a payment gateway on my system which is based on WHMCS platform. So that, i put the different API keys as its requested in my dashbord ().

Now, during the process, i got an error's page that you can see below.

The main message of the error age is "The system is not working for the moment. Try again later".

I got it yesterday evening and this morning, it is the same thing.

Can you help me to know what's going wrong ?

This is my configuration about PayPal integration in WHMCS panel.

Thanks.