Executing bash file via php on apache server

So I have hosted a webpage on my apache server and I'm trying to run some python and bash scripts when the user presses a button via PHP and AJAX.
Now my php file executes at python script (located in /var/www/html) which in turn executes a bash file (located in root/files).
On doing this manually in terminal, everything works perfectly fine.
But when I try to this via the webpage, the bash script isn't executed. (I can't place the bash script in /var/www/html because it has the command to clone a git repository to the server and it gives private key shouldn't be public error when placed there)
I already tried suggestions in this answer by adding www-data to sudoers but it is still not working as expected.
Any help on this would be appreciated. Thanks