Upgrade trailer coupling at Seat Leon

Hello Motor-Talk community, first of all: I apologize if this question has been asked in exactly the form more than once, but either I’m thinking of looking for something too stupid or… well, whatever… I bought (used) a Seat Leon model in 2017. I’m thinking about retrofitting a trailer coupling. First of all: is this even possible with the model? If the relevant thing is: it’s the 1.2 TSI, (7583 / AJZ). What’s the best way to do that? rkstatt? Or are there recommended service providers who have also specialized in retrofitting trailer couplings? Can one meet an approximate statement, what could cost such a thing in total? 800 € ? 1200 € ? More? Purpose of the AHK: bicycle holder. I do not want bicycle holder which is only clamped to the tailgate. Therefore the coupling. Thanks already for your help greeting Killerloop666