Update PHP Version for WordPress

My site is running on an outdated version of PHP (7.4.33.13), which does not receive security updates and soon will not be supported by WordPress. We need a freelancer to update the PHP version to ensure security and compatibility with WordPress. In complete transparency, someone did this for me previously, and I don't know which platform is hosting my website. Hopefully, that kind of helps you understand my technical illiteracy on this.