The version of PHP will not affect any of the data in the database.

I have contabo hosting And there not show Packages changes option

Select php not available this option

Showing this one see the pic's

In that case, you can either change the hosting provider or move to a modern forum software.

As you're on shared hosting with contabo, they didnt allow the use of the older php 5.6, 7.0, 7.1 etc.

You could try putting in a request to them & asking to have 5.6 or 7.0/1 enabled for your account.

As it is cpanel, its still available in whm/cpanel.

What about 8.0 php

vBulletin 4.2.5 is only able to work with PHP up to 7.1.x so 8.x is a no.
If you need to run newer variants of PHP you can use this:
https://vborg.vbsupport.ru/showthrea...07#post2608007

However, be advised that any plugins you use are also bound by PHP version constraints and may or may not work. Even older mods break after PHP 5.6 and don't work on PHP 7+

If addition to update the code to support newer versions of PHP you just need a PHP programmer and not a vBulletin developer.