Source: https://www.spigotmc.org/resources/goldencrates-%E2%80%A2-advanced-custom-crates-1-14-1-16.48732/
We use this plugin to allow players to open a crate as a future reward for votes, until then the keys are often sold in the Auction’s found in the Shops.
Simple, but powerful crates plugin! Create crates via in-game GUI editor, manage crate options and rewards!
• In-game GUI Editor:
▸ Change all crate settings in simple GUI.
▸ Add and modify crate rewards by drag and drop items!
• Crate Rewards:
▸ Support for custom items with any NBT tags!
▸ Execute commands when player wins reward!
▸ Define min. and max. rewards amount that player can win at once!
▸ Prevent player to open a crate when he don’t have enough space in inventory to prevent reward loss.
• Rewards Preview:
▸ Allows you to display chances in reward lore.
▸ Crate preview can be disabled totally.
• Crate Types:
▸ Attach any crate to any block in the world and open it by Right-Click! You can attach the same crate to multiple blocks in multiple worlds!
▸ Add any crate to customizable internal GUIs and open it by click!
• Crate Keys:
▸ Multiple crates may require the same key to open!
▸ Make the key virtual! Virtual keys are stored in the database.
▸ Support for offline players when giving keys.
• Crate Cooldowns:
▸ All times are supported: Seconds, Minutes, Hours, Days, Months, Years!
• Crate Animation Templates:
▸ Create your own animated rewards GUI!
▸ Define the roll speed, sounds and effects.
▸ Define reward positions and final win slot.
• Compatibility:
▸ Add custom holograms upon crate block in the world via HolographicDisplays!
▸ Make crate require a certain amount of money to open it with Vault!
• PlaceholderAPI Support:
▸ %goldencrates_cooldown_<crate>% – Displays amount of time before specified crate can be opened again.
Type /crate editor and click on New Crate!
F.A.Q.
A: No.Q: I added crate in the world, but players can’t open it!
A: Check your claim plugins and spawn-protection setting.
A: Ask your vote plugin. This plugin does nothing with voting.
• /crate editor – Open GUI Editor.
• /crate menu <menu> – Open custom crate menu.
• /crate give <player|*> <crate> [amount] – Give crate to specified player(s).
• /crate givekey <player|*> <key> [amount] – Give crate key to specified player(s).
• /crate keys [player] – Displays amount of player keys.
• /crate reload – Reload the plugin.
• goldencrates.user – User access (Given by default)
• goldencrates.admin – Admin access
• goldencrates.cmd.keys – Access to keys sub-command.
• golcencrates.open.[crate] – Allows to open specified crate when permission is required.
• goldencrates.bypass.cooldown – Bypass crate cooldown.
• goldencrates.bypass.cost – Bypass crate cost.
✓ HolographicDisplays [Link]
✓ Citizens [Link]
✓ Vault [Link]