This tutorial by snowbillr covers creating your own buttons in Phaser 3:
"Phaser 2 had buttons but they arenÔÇÖt built in to Phaser 3. In reality, they are simple to make on our own. In this tutorial weÔÇÖll break down what it means for something to be a button and how to make one in Phaser-land.
Buttons ArenÔÇÖt Scary
Buttons arenÔÇÖt some magic black box of mystery. A button in its simplest form is something that responds to clicks.
ThatÔÇÖs it.
Hover states, animations, fancy effects, whatever, are just icing on the cake. Phaser makes it really easy to make something clickable, so letÔÇÖs start with building that."