Create a task that allows you to select multiple images and rotate them.
This will run the task on the files and folders selected from within FileBrowser.
Use files from:
Change the top dropdown to "Selection when task is run"
Then tap "Insert Step"
Rotate Images 90 degrees.
In the new section, change the top dropdown to "Rotate images"
Change the second dropdown to "90 Anticlockwise"
Run task:
Leave it as "Manual".
Tap "Close"
To run this Task simply select your images and use the toolbar actions menu and select "Run Custom Task" selecting your new "Rotate Images" task.