Baker (Commercial) Client Services Raleigh United States
If you want to change the version 7.3 to latest version of php. i.e 7.4. Then it depends on the hosting service provider.
If you are using shared hosting services from Godaddy., Hostinger or Hostgator then inside the control panel there is an option to change the php version.
However if you are using cloud hosting and have installed apache server or Nginx Server then you have to upgrade the PHP version or install latest version of PHP.
sudo apt-get install php libapache2-mod-php php-mcrypt php-mysql
Use above command to install fresh copy of PHP.