I was able to resolve this issue after several days of first getting ioncube to be recognized by my nginx server and then the this "realpath(): open_basedir restriction in effect. File(/www/wwwroot) is not within the allowed path(s): (/www/wwwroot/blesta.vpsjz.com/:/tmp/)" error. Well not exactly to the letter, but here's how I fixed it or got it to work.
On my server the php.ini file was shared by all versions 5.6-8.0. All I had to do is to edit the 7.4-fm php.ini via Hestia, and the changes were made globally. on the line #305 in my case I added everything that was included in the () after "File(/www/wwwroot) is not within the allowed path(s):" which in Hejiaqiao case is /www/wwwroot/blesta.vpsjz.com/:/tmp/. So it should appear as:
; open_basedir, if set, limits all file operations to the defined directory
; and below. This directive makes most sense if used in a per-directory
; or per-virtualhost web server configuration file.
; http://php.net/open-basedir
open_basedir = /www/wwwroot/blesta.vpsjz.com/:/tmp/
Next
log into the VPS or server, website or whatever as root in my case.
navigate to the folder where Blesta is located. In my case:
cd /home/user/web/example.com/public_html NOTE:
Be sure to drop all the tables and what not from the database that your using for Blesta before starting step 3.
Now RUN
php ./index.php install
Now just follow the onscreen prompts such as providing the Database, Database User Name, and Password and the setup should complete as normally.
I hope that this helps. I have been trying to get this software to work to try it out for a week.