Php update required for plugin

Trying to update my website php version, but unable to update php version. It it hosting company’s responsibility to handle PHP updates? How can i update my php version for my https://bit.ly/2PydKUa .

There is a plugin which is not updating any futher just because it required new php version and i can’t figure out a way to update the plugin or update the php version for my wordpress website.

The error says “You have version 1.5.2.1 installed. Update to 1.5.4.2” This update doesn’t work with your version of PHP.