This site allows you to co-solve crossword puzzles with your friends. To use it, you will all need accounts here; happily, those are free. The expectation is that you will use Zoom or some other conferencing service to talk to each other while you solve (though whether or not you do is entirely up to you).
One person will need to host the game, and will need to have a puzzle to solve in either .puz, .jpz, or .yap format (no puzzles are provided by this site—the host has to have one they can upload).
The host will create a room and people who want to solve the puzzle will join the room to co-solve. The host can set the room to be private, in which case it will not appear in the list of available rooms—the host will need to give their guests the URL to the room some way extrinsic to this website. The host can also create a password people will need to join the room.
Full instructions are available, both for hosting a puzzle and for playing one from inside the Crossword game, by clicking the button. In addition to the cooperative mode you would expect (everyone sees everyone else's letters they fill in), there is a competitive mode that is unique to this site, where you compete with each other. If you are going to play the competitive mode, you probably want to read the details, becausse some bits are non–obvious.
Currently, there is only one other game supported—Exquisite Fruit. It has been played once, and had some bugs; I believe I have fixed them all, but I cannot test properly as I cannot create enough players. But it ought to be working. Please let me know if it isn’t.
There are instructions available if you create or join a room and click the button.
If that happens, the site will need to change to generate enough money to at least pay the hosting costs. I’ll figure out what to do if that ever happens. If I can get an ad service I’ll likely go that route, with an option to pay a subscription fee to eliminate the ads. If I can’t, then I’ll likely go to an annual subscription fee.