I want flirefly to use a character from an image I've uploaded. It only uses my image as a reference

Is there any way of getting Firefly to extract an exact character from an image I've uploaded? We have a cartoon character and want to put him in different scenes and costumes but Firefly (and every other AI image generator I've tried) will just use the image as a reference and then produce something completely different. Am I using the wrong prompts? This must be possible somewhere now with some AI software!

Please help. I came to firefly as read that it could achieve this.