Resolve WordPress PHP Version Error

My WordPress site throws the message:

“Composer detected issues in your platform: Your Composer dependencies require a PHP version >= 8.3.0”.

At the moment I don’t even know which PHP version the server is running, and I’m not sure whether any particular plugin or theme is behind the problem. What I need is a clean, end-to-end fix that gets both the public site and the WordPress admin area working normally again.

Here’s how I see the job:

• Pinpoint the current server PHP version and, if it’s below 8.3, upgrade or adjust the hosting settings so that Composer stops complaining.
• Audit core WordPress files, active plugins, and the theme for compatibility with PHP 8.3+.
• Resolve any conflicts you uncover—this could involve editing or replacing outdated code, updating Composer dependencies, or recommending alternative plugins/themes.
• Test thoroughly to confirm the front end and wp-admin load without errors.
• Deliver a brief, plain-English summary of the steps you took and any ongoing maintenance I should keep in mind.

Please let me know:
1. A ballpark cost for the work.
2. How soon you can start and the estimated turnaround once you’re in the dashboard.

You’ll receive full WordPress admin and hosting (cPanel) access as soon as we agree on terms.