You are runing an outdated version of PHP !
Your version is : 5.6.40
Minimal version : 7.2.0
Recommended version : 7.3 - 8.x (all version <7.3 are "End of life" and don't have security fixes!)
Please read offical PHP recommendations
Please update your PHP version form your admin panel. If you don't know how to do it please contact your WebMaster or your Hosting provider!