Error 500 and/or php version

My client called to say his site is not working. The front-end is loading but with mixed usage errors, the manager gets Error 500 error. No idea when this happened. The site hasn’t been touched for months.

Modx 2.7.1
PHP 7.2.29
Shared Hosting at Hostmonster

I deleted the core/cache
I renamed the .htaccess in the root and in the manager
I disabled all the plugins

Now the front-end gets Error 500
The manager says “Wrong php version 5.2.17…”

I’ve confirmed the server php is 7.2.29

I tried uploading the setup folder and running setup. That produced an invalid core path, has to contain a trailing slash.

/home5/xxxxxx/public_html/setup/core/

I haven’t tried editing this to remove setup from this path because I’m not sure what else might be incorrect or if it might fail partway through the process.

I’m stuck.