PHP Code Updates for PHP 7.3 release

We have had some custom PHP pages built a few years back. We need to update to a new Cpanel that needs to have this PHP code updated to work with updated PHP update.
Hosting Company said this…
If you can find a programmer to do the work, they would need to update any of your PHP pages with current PHP code that works with the current PHP 7.3 release.

There are a few pages and links I use for my business that are an integral part of my needs to conduct a portion of the business. If there is anyone there that can help me with a code update that will work with PHP 7.3 release please get back to us.