Can I upload HDR images I created myself and have them edited?

Yes — you can upload pre-merged HDR images. Just make sure the image has visible detail outside the windows and no missing data from over- or under-exposed regions.

What the AI needs to work with

As long as every part of the image has visible data, AutoHDR can produce a beautifully edited photo. If areas are fully blown out or pitch black in your merged file, those areas can't be recovered.