In order to use forms in cms pages, you must enable "Allow iframes on HTML fields" and disable "Use HTMLPurifier Library" (https://prnt.sc/tcsx77) from Preferences -> General
Also while using mailchimp embedded form you must "Disable All Javascript" (https://prnt.sc/tcsyaz) as script tags are not allowed in TinyMCE text editor.
Hello @John
If I am getting it right then you want to print the payment status on the invoice.
If yes, then it cannot be done via default feature of QloApps. We need to customize it.
Please raise a ticket at https://webkul.uvdesk.com/en/customer/create-ticket/