It’s a payment gateway issue and there is no relation with theme activation or something else.
Moreover, we can see that you have downloaded the theme and still not verified and activate your license.
You still not mentioning what is the exact issue or didn’t provide a screenshot of the error.
Please Note: Without verifying and activating your license you will not get full access to the theme, import demo data, core features, etc.
Please watch this video tutorial to activate your license to get full access to the theme, import demo data, core features, etc. https://www.youtube.com/watch?v=5EXUOFs8_Wk&list=PLbmIKrgYlRbpJbpC67IFMoQkrQP7NHuK2&index=2&t=0s
Best Regards,
ThemeLooks Support Team