I followed this guide https://docs.gibbonedu.org/administrators/getting-started/installing-gibbon/install-ubuntu-debian/ to install Gibbon on ubuntu in digital ocean.
I installed it successfully but when I login and get redirected to https://my-domain/index.php I get the following common error:
An error has occurred. This could mean a number of different things, but generally indicates that you have a misspelt address, or are trying to access a page that you are not permitted to access. If you cannot solve this problem by retyping the address, or through other means, please contact your system administrator.
I tried to apply fixes from related discussions but could not fix it. I think I got the address right. The permission as well since I followed the tutorial.
I need some help please.
Thank you in advance