Aside from upgrading to the paid version there appears to be no solution to this problem. Time to go back to the latest release of Zen Cart v2.0.1 and center my attention/efforts to a viable payment gateway on a current stable version of Zen.
A BIG THANKS to EVERYONE who has taken time, left suggestions and insights. I sincerely appreciate the help

Final thoughts: Perhaps the available free version of Square webPay module has begun it's entry into "Deprication"?... At least, this is the reality in my case. This module is not compatible with PHP versions above 8.0 and everything right now is moving upwards of PHP 8.0 making the current paid version of Square webPay the only way to go for accepting Square Payments via checkout...