I have a MultiPHP Manager on my WHM and I have installed Magento 2.2 with PHP 7.1.9. However, whenever I execute a simple cli command I receive an error Magento supports 7.0.2, 7.0.4 and 7.0.6 or later - see screenshot. How do I fix this?
As you can see, still your PHP server is using 5.6.31 version. So you need to upgrade your PHP in order to use Magento 2.2
Your console is still relying on PHP version 5.6.x. It is true that using your MultiPHP manager you are running your site on version 7.x. But it means your apache PHP version is only changed. However, CLI is not relying on Apache configuration, which still relies on your default PHP setup. So you need to upgrade that too.
You can fix this in many ways. A good start is here. Then look for the best way that will work for you.
When you have multiple PHP version on your server then you need to specify the php version in command line because from multiple PHP version, one PHP version is set as Default so please run below command for PHP7.1:
/opt/plesk/php/7.1/bin/php bin/magento cache:flush; /opt/plesk/php/7.1/bin/php bin/magento indxer:reindex;