After setting up Apache it's not serving PHP files, but showing the contents of the files instead

The error I got is in this url: url in browser: http://localhost/ error in browser: https://justpaste.it/d82bd

What am I missing here?

I copied the file ipconfig.php (given below) from ipconfig.php.example but no luck.

I give permission to the files using this:

cat /etc/systemd/system/php-fpm.service.d/override.conf

ReadWritePaths = /srv/http/ipconfig.php
ReadWritePaths = /srv/http/uploads/
ReadWritePaths = /srv/http/application/logs
ReadWritePaths = /srv/http/vendor/mpdf/mpdf/tmp

 $ ls /srv/http

 application     docker-compose.yml  ipconfig.php.example  uploads
 assets          Gruntfile.js        LICENSE.txt       v1.5.11.zip
 composer.json   htaccess        package.json      vendor
 composer.lock   index.php       README.md
 CONTRIBUTING.md  ipconfig.php       robots.txt

We are on Archlinux

We created a database in mariads as explained in Archwiki

$ mariadb -u root -pa
MariaDB > CREATE DATABASE invoiceplane;
MariaDB > GRANT ALL PRIVILEGES ON invoiceplane.* TO invoiceplane@'localhost' IDENTIFIED BY 'password';
MariaDB > FLUSH PRIVILEGES;

further

$ cat /etc/httpd/conf/extra/invoiceplane.conf
Alias /invoiceplane "/srv/http"
<Directory "/srv/http">
    DirectoryIndex index.php
    AllowOverride All
    Options FollowSymlinks
    Require all granted
</Directory>

$ cat /etc/httpd/conf/httpd.conf

result

$cat /srv/http/ipconfig.php

result

I am sorry but I am a complete newbie but I tried to do as suggested in wiki and docs.

the "error" you pasted in justpaste.it is not a real error message, but you are seeing the whole index.php file. This means probably that PHP on your server is misconfigured.