Referral [1.7-1.20+]

This is a simple referral plugin.
How does it work?
When a player gets invited to play on the server, The player that invited the other player does not use /ref <player>, but the player that joined tells the server who invited him/her. The player is only able to tell who referred him/her once.

Referral V2:
The referral plugin has been re-coded and has been made public.
The plugin now also contains better autocomplete and async database requests to prevent server stutters.

Referral pro free

Permission:
- Referral.ReferPlayer - /ref <name> - Tell the server who invited this person
- Referral.RefReject- /ref reject <name>
- Referral.RefAccept - /ref accept <name>
- Referral.RefCount - /ref total
- Referral.RefTop - /ref top
- no perm - /ref help

Admin
- Referral.Reject - /ref reload
- Referral.RefAdmin - /ref Admin ['Reset', 'Remove'] <name>

Old perms / command use

- Referral.ReferPlayer- /Ref
- Referral.Admin - /RefAdmin commands
- Referral.RefCount - /Refcount
- Referral.RefAccept - /RefAccept
- Referral.LastReward- /RefLastReward
- Referral.Reject- /RefReject
- Referral. RefTop- /RefTop

Soft dependency:
PlaceholderAPI - when it's installed use /Papi ecloud download Player for the default names

Commands:
/ref <player> - Referrals a players and gives rewards
/ref Total - checks self or /ref Total <player> - For other players
/ref Accept <player> - Or click the button
/ref Reject <player> - Or click the button
/ref Help - Shows list of commands the player can use
In older versions of the plugin <player> used to be <Player>!

Admin
/ref Reload - reloads the plugin
/ref Admin ['reset', 'remove'] <player> - Resets or removes the player from the database
In older versions of the plugin <player> used to be <Player>!

Old command use

/Ref <Player> - Referrals a players and gives rewards
/RefTotal - checks self or /RefTotal <Player> - For other players
/RefAccept <Player> - Or click the button
/RefReject <Player> - Or click the button
/RefHelp - Shows list of commands the player can use

Admin:
/RefAdmin Reset <Player> - Removes the used referral from player
/RefAdmin Remove <Player> - Removes the player from database
/RefReload - Reloads plugin

PlaceHolders:
%referral_total% - Gives the referral total of the player
%referral_refed% - Tells if the player refed

You can use placeholders in places where already is a placeholder.

Tutorial:
Thanks to: SoulStriker

The config:

Config

https://pastebin.com/eAuaGg8P

Available databases:
Local, MySQL

Supported versions:
1.7 - 1.8 - 1.9 - 1.10 - 1.11 - 1.12 - 1.13 - 1.14 - 1.15 - 1.16 - 1.17 - 1.18

Is there something that isn't working please DO NOT USE the comment section but join the discord server HERE.
If the button doesn't work use this link https://discord.gg/teMrM7Z

Looking for a Referral system that has: UI, Offline player support, Random rewards, Referral codes and Rank-based rewards.
Click on the link below.