I find no way to do this. How can I drag and drop on an ipad!!! Why can I not simply aceess the files app or other apps files?
Please use the "Open…" command in Textastic to open files from the Files app using the iOS document picker.
You can also use "Add External Folder…" to add folders from iCloud Drive or apps like the Git client Working Copy as an external folder to Textastic.
Have a look at this topic in the manual for details: https://www.textasticapp.com/v9/manual/integration_other_apps/external_files_folders.html
Customer support service by UserEcho