HA container + Mosquitto - how to benifit from MQTT Discovery (dummy question)

Hello,
I’m new to Home Assistant. I’m trying to create an automation that will trigger a Shelly Wave Shutter when a button on a dingz is pressed.
Mosquitto is up and running, and it is receiving some information from my Dingz.
According to the dingz MQTT manual, the dingz provides mDNS discovery, which is not the same as MQTT discovery, isn’t it?
Using MQTT Explorer, I can see the minimum set of information in Mosquitto.
Is there any chance that I can benefit from MQTT Discovery, given that I have plenty of these switches?
I tried to add it using ‘Add MQTT Device’, but there is no template for simply reading an event to see when the button was pressed.

Do I really have to go through the configuration.yml file as explained in MQTT Event - Home Assistant?

So far, I have read

I’m sorry if some of the questions sound silly, but I can only work on it when the family is in bed, i.e. late at night. My mental capacity is a bit limited.