Normally i would open the pages of the appstore component only to admin users.
If a regular user needs to do an upload, create your own pages for this and only call the microflows/actions you need from the module. They will get lost in the (necessary) complexity of the appstore component.
I highly discourage modifying appstore components, because this will inevitably lead to problems when you need to upgrade your application to a newer version in the future.
Hi Ashlin,
please take a look at this learning path first: https://gettingstarted.mendixcloud.com/link/path/38
Many concepts of implementing custom logic using microflows & security are discussed there.
With this basic knowledge a lot questions will be answered you have the right basic knowledge to understand the more complex answers on your questions.