Inigo Idiakez's side reached the final in dramatic circumstances, overturning a two-goal deficit late on against Oxford United in the southern final, before defeating them on penalties.
Entry for supporters is free of charge for the 7pm kick-off, with the Main Enclosure and Main Stand open.
Refreshment kiosks will be available on the night.
Make sure you're at Kenilworth Road to cheer on the boys, who warmed up for Wednesday's big game by hitting seven past Portsmouth on Saturday at The Brache.
Jake Peck and Josh Neufville got a brace apiece with Michael Shamalo, Arthur Read and Drew Richardson also on target in the 7-1 win. Well done lads!