How add zoom [+] and zoom [-]

Hello!

Could someone tell me how to enable these buttons?

image

You can easily create something yourself by using the ZoomScroll module

const zoomScroll = modeler.get('zoomScroll');

zoomScroll.reset();
zoomScroll.stepZoom(1);
zoomScroll.stepZoom(-1);

The buttons are not part of bpmn-js, but simple HTML elements which execute these methods.

As far as I know they are already enabled. What exactly do you want to achieve?