How to download a list of URLs saved in a text file on iOS?
There are at least a couple of ways. Unfortunately there is no command line interface on iPadOS so WGET is going to be impossible to use. And unless the text file is ENORMOUS there is no need to zip the text file, though there are zip utilities for iOS.
iCloud allows for the synchronization of data between apps on both the Mac, iPhone and iPad. If you have iCloud drive you could paste the URLs into a pages.app document and save it there. Then you can open it on pages.app on your iPad.
If, like me, you don't have iCloud drive set up you can log into iCloud.com on your Mac and paste that text into a new notes document. This will then sync to all of your iCloud devices, including your iPad.
If you have a blog you can upload the text file to the blog and then go to that file on your iPad:
http://myblogwebaddress.com/textfileiwant.txt
Also if you have iCloud drive you can put the file in one of your iCloud folders and then use the files.app on your iPad to access the text file.
There are other ways but, hopefully, that will get you started.