Every element can have interactions added to it. Interactions are anything that a player can do when they approach the element. This ranges from something like setting off a confetti cannon, to portaling to another room, to minting an NFT.
Each interaction is covered in more depth in the Interactions section of the tutorial doc.

Adding an Interaction

To add an interaction, select an element and go to the interactions menu, marked by a lightning icon.
Once the interaction is added, you will see little magic dots floating up from the element. This is the indicator that the element has an interaction! As a builder, you will also see an icon that indicates the applied interaction.
Once there is an interaction on an element, you can then edit the interaction zones. This sets the area where a player can use the interaction.
In the example below, there is a portal set around the base of the tree. Here, you can see the player is overlapped with the interaction zone, so they see the prompt to interact with the element, "Tap or press E to enter portal."
You technically can add multiple interactions to one object, but do so with care — you do not want to confuse the player by prompting them with too many things to do. It is up to you as the builder to create experiences that make sense!