Tickets seated together?

After many attempts I managed to get 3 tickets for LA match and after purchasing it says seats will be assigned later and cannot be guaranteed seated together. In my confirmation email it says I can go to my “Ticket purchase history” to use the “sit together” function, but right above this it says the sit together function is only available til Feb 22nd…. Every part of this process has been so difficult and confusing. Does anyone know if there is another way to request seats together? Thanks!