Update Custom fields value on another entity

Hello,
When we create coupon, can we update on its custom field, a custom field of a customer who is udpate on ticket.

Exemple : Entity Customer. Name : Mr Brown. Custom Field : Category : VIP
Entity Coupon. Name : ZK45648DF Custom Field : Category : “Blank until the update”

So I would like to update Category Value of Customer Entity on Category Field of Coupon Entity
Is it possible? What is the tag to do it? I tried {ENTITY DATA:Category} but it doesn’t work

Thanks

Since both entities have “Category” custom field you need to use long tag format. For example {ENTITY DATA:Customer:Category}

Many thanks, I’m going to try this tag