The photo plugin (starting from version 2) can deliver non-image files from any directory of the phone storage (/storage/emulated/0/) to the server.
Here's the sample configuration:
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This configuration will require devices to send all .txt and .log files from /storage/emulated/0/logs to the server (/var/lib/tomcat9/work/plugins/plugin/photo/).
You must add the Photo Plugin mobile agent to the directory (available in the Premium package).
Note that some directories (/storage/emulated/0/Android/data/*) which are private to other applications are not accessible to Headwind MDM on Android 11 and above (here are the details: https://developer.android.com/about/versions/11/privacy/storage).