PayPal from App Inventor

Hi. We are calling a simple .html file (code generated by PayPal) to implement online payment.
The .html file contains Plan ID in PayPal to call the correct subscription plan.
After testing with a P-Plan we have created a production subscription plan in PayPal and generated the html code. This html file works just fine when we call it from a browser, but when calling it from App Inventor block it continues to fetch the "Test subscription plan" in PayPal.
Any suggestion?