iOS apk file installation on devices

I have been trying to research how to install the apk file that is sent
via email for my iOS device from thunkable X nothing is helping.
The problem is that the apk file can not be downloaded and I can’t
see the device management where I can trust Trust Rappidly Inc .
I already installed the profile on my iOS device . How can I fix this?
I am using an iPad Pro (12.9-inch) Software version 13.3 and also
size screen during the development , can I just use the live test
during development or maybe you can change the size of the
UI screen on the Thunkable X platform
?

Thanks.

Already fixed the problem already,Thanks.