I also made a tutorial on how to basically import multiple CLI images at once, though please watch Payu's tutorial before trying this:
https://youtu.be/JEsgP3e6n4s
Some things to keep in mind are
1. You need to allow Termux access to files, open Termux and type termux-setup-storage and enter.
2. Install JQ, type pkg install jq and if it asks you to press y or n, press y