Is it yours OP?
You need a more specialist agent. 7 really ‘meh’ photos aren’t going to convince anyone that Barbican living is for them. https://themodernhouse.com do this kind of thing well. You’re looking for a niche buyer, as the responses on this thread will tell you, so you need to put in the work and the money to get the sale.
The flat needs to be staged. At the moment (and I say this as someone who loves brutalist architecture and would give my right arm to live in the Barbican) there is very little in those photos that sets this flat apart from any ex council flat in any other estate in central London. That bedroom could be any bedroom in any house in any city or suburb going by the decor.
Sorry to be brutal(ist) but 🤷♀️