I maintain a Discord server for my Twitch Subs/YouTube members/Patreons so they can interact with myself and the Hooglandia Community even when I am offline. We talk about Games, Politics and life in general.
There is no direct invite link, instead you join the server by linking your Discord account to your supporter account. Below are screenshots for Twitch, but YouTube and Patreon are almost the same.
On the desktop version of Discord go to: User Settings > Connections > Twitch
Q: Can I join from mobile?
A: In an awkward manner. If you open the desktop version of Discord in your mobile browser you can technically link your accounts through there. The Discord mobile app does not support linking accounts currently.
Q: If I unsubscribe am I removed from the server?
A: Yes. After you have been unsubscribed for 3 days you are automatically removed