Is fusion management a real modelling agency uk?

I haven't heard of it. Be aware that even the ones who are not scams don't promise any modelling.

REAL agencies do not charge up front fees, THEY DO....they are like many 'model/talent  businesses set up to scam desparate people who want to get into the entertainment industry and have no clue about how the industry works.....

Find a real agency who will interview you, will take some test photographs and will sign you up ( or say thank you, no thank you) if they take you on  so you sign a contract and they will arrange for a portfolio of photos which doesn't cost you up front money and will get you work and pay you

Looks like it from their online ads.