PHP Code: code not showing on page

i put a paypal button form <form action=”https://www.paypal.com/cgi-bin/webscr&#8221; method=”post”>….</form> in the ‘Save code’ section of the plugin and pasted the shortcode to a WP page. On viewing the page is blank (no button). I surrounded it with <?php ?>

am I using the right plugin?
if so, how to fix
the goal is to have this paypal button form connect to my idevaffiliate software to keep track of affiliate purchases.

thanks

https://www.ads-software.com/plugins/php-code-for-posts/