Some friends downloaded ARK from Epic Games last night, want to join my server hosted here. Where do I add the command Crossplay?

I am also trying to get this to work...

I found this which explains it but when I enter the arg's for server boot it gets hung up at 97-98%

https://survivetheark.com/index.php?/articles.html/community-crunch-225-crystal-isles-anniversary-event-epic-games-store-and-more-r1569

You have to do two things to crossplay with Epic:

1) Turn on the option on the Advanced Tab.

2) Turn off all of your mods as Epic doesn't support Mods.

3) Reboot your server after doing 1 and 2.

4) As most game stores have throttled their bandwidth as of late, you'll need to WAIT. Patiently. Not like a three year old in the backseat of a car trip, but like an Adult in the front seat of a car trip. As ARK is in a "release" state there is a LOT of downloads, patches, updates and bug fixes going on that normally happen when a real game company does QA testing.

Expect your server to be updated twice a day minimal for the next week. Especially if you're using Crystal Isles.

But finally, when your Vanilla ARK Server is online with CrossPlay enabled, EGS players still only can use the In Game Server Listing of ARK to find the game... which is famously a piece of garbage.

Refer to https://arkservers.io/help/faq/server_listing for additional info on that part.