In case that you can’t use the PHP Version Manager in cPanel, you can change your PHP version by adding a line of code to your .htaccess file of your wordpress website.
To apply these changes you can use a FPT software like FileZilla (this is what i usually use). Locate your .httaccess file and at the top of the document add the following line of code:
AddType application/x-httpd-php71 .php
Or this line of code if the first one doesn’t work for you
Action application/x-httpd-php71 /cgi-sys/php71-fcgi-starter.fcgi
Here is an example
That’s all there is to it.