Resale tickets

Hi! I have 2 general admission tickets for the show on the 15th in London that I want to sell. Now, I’ve never really sold tickets before, but from what I can see, ticket transfer is unavailable for this tour, so does anyone have any suggestions as to how I can sell these tickets outside of Ticketmaster? Is the only other option to just meet up with the buyer the day of the concert or will they open ticket transfer a week before perhaps? I’ve tried listing them on Viagogo but they won’t let me without transfering the tickets so I don’t really know how they even have tickets available but I’m generally looking to avoid 3rd party sites, that would be the last resort because of all the fees (both for me and the buyer).