Best way to incorporate a VTT?
For easy maps/VTT access, I used Owlbear Rodeo for a combat in a game. Worked well. It's free, built for 5th edition and is fairly versatile. I just posted a link in the thread at the start of combat. Conversely, the map section of the game could work. Take a screen shot and utilize that, post it in maps (or just as an image in the combat thread).
The drawback is two-fold:
First, anyone can move any icon. While this isn't a HUGE deal, sometimes players move things on accident. This could be alleviated by taking the 'snapshot' option, as listed above.
Second is the fact that for the duration of the fight, the 'host' (GM, usually) would need to keep the map open on their browser. Now, there are two things that can alleviate this - first being the snapshot posting. Second is the website 'remembers' the map, and the location of all tokens, based on your browser's cookies. For example in my weekly table top, I can set up the map, close my lap top - show up at game and send everyone the link when combat starts. If we need to pick up the following week, even if I've closed my browser out, as long as I've got the same laptop, it has everything stored.
There ARE plenty of easier methods (Roll20, as mentioned, just to name one). However, you may have issues with players being able/willing to set up accounts on the associated site or download/install/config any downloaded program.
Owlbear, and a few others, just require logging into a website. No login required - unless you set up a password for the game.