Any widget can have an action so you can make any widget behave like a button.
The oh-button is a component that can be used to construct a more complicated compound widget (there are examples on the marketplace for details).
But if you want simple, you can use an oh-label-card or oh-label-item (depending on whether the widget appears on it’s own or as a row inside a list card) and just set the action to do what ever you want it to do (command an Item, run a rule, open a pop-over, etc.). You can use expressions to change icon, color, text, etc. based on the state of the Item if desired.
For an example see Door and Lock Combo which is a simple list item widget that shows two Item (a door sensor and a smart lock opener). The icon, badge text, and colors change based on the state of the Items. Clicking anywhere on the widget commands the lock to open/close.