Or will my players still need to download and access the online player? I’ve got it integrated with Foundry and it works beautifully for me, the DM, but I’d like it if it would play in game and not require my players to download an additional thing.
Yeah, there’s some awesome mods now. 
For the moment, yes, your players will have to follow the first 3 steps here:
Here’s a video of me going through the process in just 3 minutes:
Note, however, we are right now working on a FAR easier solution for your players. Definitely watch our socials and this forum for some news as soon as we are able to share!