Just thought I'd make a quick tutorial on how to create kits for a specific usergroup (VIP, Discord Users, etc) as I see a lot of people are having a few issues. Please note that the steps in this couldbe seen by some as incorrect, however this worked for me with no issues whatsoever. For my example, I created a better "starter" kit for members of our Discord only. I have a custom mod that syncs Discord with the server so I do not need to manually assign this permission to individual players, but I will ensure adding players to the group is included in this tutorial. 

1.  Create a permissions group and call it what you like. For example, "oxide.group add discord". Please note, if you do not have an automatic syncing mod between Discord and your server, you will need to manually grant your Discord users this permission.
2. Go ahead and use /kit and create your kit; for me I left the "permissions" blank for now.
3. Once your kit has been created, head to oxide/data/Kits/kits_data.json
4. Find your kit you'd like to add the permission to, and manually add it. Example below;
   
   "Name": "Discord Starter Base Kit",
   "Description": "The Starter Base Kit for Discord Members. Join our Discord to gain access!",
   "RequiredPermission": "kits.discord",
   "MaximumUses": 1,
   
   
5.  Reload the plugin, and use /kit. For my example, this is what I saw https://imgur.com/a/hNexqjM. Again if you don't have an automatic syncing mod between your Discord and your server, you will manually be required to add your Discord members to this group. To do this, you will need their Steam64 ID. Once you have this, you can use "oxide.usergroup add <player_name or STEAM64_ID> group_name"

I hope this helps anyone who has been having issues. :)