Hi Tuan,
With Joomla 4 alpha 1, 2, 3, or 4 when I try to access Configuration, I obtain:
"Error: 0 Call to a member function setup() on boolean"
Is it the same for you? I use a Mamp environment
I haven't had time to try it again yet. It might related to an option which I added recently (using Joomla core field for selecting terms and conditions)
As mentioned, I will look at it during this weekend
If it's really needed, I can check and send you an older version of the extension which works with Joomla 4 (before I added the above mentioned option) and it should work well
