When I install a template or script, I need to edit php.ini settings.

DirectAdmin File Editor Can do it easily. But it does not support Php 8.1 and above.
But you can do it early as below:
Just login to SSH with root access,
Then open it with you file editor like nano
As a last step add your desired php versions as below:

Then save. That's all,
Here is your php.ini editor for Php version 8.2


DirectAdmin File Editor Can do it easily. But it does not support Php 8.1 and above.
But you can do it early as below:
Just login to SSH with root access,
Code:
mkdir -p /usr/local/directadmin/data/templates/custom
cd /usr/local/directadmin/data/templates/custom
cp ../edit_files.txt .
Then open it with you file editor like nano
Code:
nano edit_files.txt
As a last step add your desired php versions as below:
Code:
/usr/local/php82/lib/php.ini=user=root&group=root&permission=644&hide_if_not_exist=yes&secure=yes
/usr/local/php83/lib/php.ini=user=root&group=root&permission=644&hide_if_not_exist=yes&secure=yes
/usr/local/php84/lib/php.ini=user=root&group=root&permission=644&hide_if_not_exist=yes&secure=yes

Then save. That's all,
Here is your php.ini editor for Php version 8.2
