Tailfin universal thru axle wont fit my bike

hey, just bought tailfin rear rack system with universal thru axle but turned out my bike has some weird ass mountint bolt at the rear. That bold has two threads one on top that screws into derailleur and tighten it to frame and thread inside which is where original thru axle screws in. Unfortunately tailfin thru axle wont go trough that bolt. I dont even know how that type or bolt is called, what are my options here? is there any counterpart that holds the derailleur like that but will let tailfins axle go trough?

my bike is Cube reaction c62 Pro Blackline 2025