How to add players to the campaign?

I sent the players the link, they joined, and now I see them in the campaign details page. However, in the app I don't have the option, for example, to assign a character to one of the players.  Is it because I need to wait for them to get in the game itself?

Correct, they need to enter the game itself before they can be assigned anything in-game.  - Gauss

Hmm. That's feels pretty inconvenient. I can create all characters, upload the images, the character sheets pdfs (still thinking about whether to upload those) but then I have to go through each item after the players have connected to assign each one while people wait? [Edit: By which I meant: "If it's both inconvenient and easy to change, I must be doing something wrong." Maybe the correct protocol is to somehow tie everything to a character and then, in-game, just link the character to the player, which would take seconds.]

All they have to do when they join your game is hop on the board once and you can come in any time and assign what you want. They don't have to be online for you to do it. All this does is registers them into the board itself. If you want them not to see anything just make a welcome page with a brief summary about the game and lists the time and day of the game. Put the player ribbon on it and that will be the page that everyone will see when they enter the gameboard.

Perfect. Thank you.