How to change PHP version for Bitrix?

Question

PHP

Friends, how to change PHP version from 7.0 to 7.3?
The server (sort of) has PHP 7.3 installed. At least php -v (over SSH) shows that the PHP version is 7.3.
And in the Bitrix control panel, the following warning constantly appears:
"Error
You are using PHP version 7.0.33-14+ubuntu16.04.1+deb.sury.org+1, the product requires a version of at least 7.1.0 to work. Please update PHP or contact your hosting technical support."

Answer 1

Depends on the PHP mode. Most likely you have CGI or equivalent. See the host settings accordingly.
In general, it is better to use the Bitrix environment. It is very demanding on server settings. Step aside and nothing works.