cron when using wp cli

I've installed WP CLI via root. User account has jail shell access. In the console, I can execute WO CLI fine. But when trying to set up a crontab within the user's cpanel - to execute a command from a plugin on a WP CLI site - I get following errors;

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/usr/local/bin/wp --path=/home/accountusername/test.example.com/ import increment specials

Status: 500 Internal Server Error So then I realised I need to run it like the below -

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/usr/local/bin/php /usr/local/bin/wp --path=/home/accountusername/test.example.com/ import increment specials

but the result: Error: Invalid value specified for positional arg. Any help appreciated. I did look at these, but they have not helped: