FormStack Embedded Form

I have a very small Laravel website which is actually an API. It has a FORM which user fills and data is stored in Database. The form is actually build in FormStack and I have embedded it in my Laravel view via Javascript Embed method to display it.

Now I have two concerns:

1. When I use my API URL in postman, the embedded form cannot be shown in POSTMAN preview. I have added text above the form and text is shown but not form. What is the reason for that?

2. What is the best way to make an APK of this Laravel API so that I can deploy it on Android/Phone or Tablet. This allow the Android user to access that form via Andriod App, fill the form and submit it.

(Why I need APK, it is because so that FORM can be use offline/without internet access. Also don't want to use it via Browser)

Need Suggestions