Image Transparency

How to open TIFF image with transparency (alpha channel) and save it with transparency?
This for example:
266977_873536_637250512540000000_637250513500000000_96_1_44_428_resized.tif (1.2 MB)

Also the same question with RawTherapee CLI.

Unfortunately this is not possible in RT.

:frowning: Thank you.