Setup a Creator

Create a Field

After making the design of the field,

If you want lootboxes to have animation, Add Animator component, create new Animator Controller, add it to Animator. 

Make Animator Controller like this; Add Bool 'open', and make a state like the following image.

Add Audio Source component if lootbox makes sound. Set Spatial Blend to 1. Add audios on Open Audio and Close Audio in Lootbox component.

Also, add those lootboxes in 'Lootboxes' on Field Manager.

Export a Field, Play in the Field