Welcome, Dear Imad,
Thanks for reaching PayTabs out on our Developers Community. My Name is Osama El-Hamahmy the technical support team and I will be looking into this post and following up with you.
Kindly follow the instructions on our solution article Drupal Plugin - Installing to install the PayTabs plugin.
You should also know that we are providing you with a great "Solutions Portal" that includes so many articles that can walk you through any situation such as the "The How to & The What Is (FAQ)" category which contains the technical and non-technical FAQ, and the "How to Integrate with PayTabs?" category which contains all the available methods to integrate with the fully detailed documentation and "Troubleshooting Your Issues/Errors" category which will allow you to trace and solve your issues without seeking for any assistance.
Please don't ever hesitate to comment back if you still have further inquiries. Let me know if there's anything else I can help with.
Glad to be always in help.
Hoping you have a profitable and successful trade.
Imad al Din
I have built my website store with Drupal and I want to install the PayTabs plugin for the payment transactions in my store