Only slighly off topic... Node-Red - how to build a text string that referenced a msg.payload

I have my project working fine from an engineer's perspective but I need to tidy it up a bit.

When my Puck.js detects a button press, the Espruino-Hub/Node-Red servers send an SMS using Twilio. In Node-Red it finds the msg-payload value which is the cumulative number of button presses since power cycle.

The problem I am having is my lack of understanding of how to work in Node-Red with messages.

In many programming languages I wand something like

printf("Alert, the button was pressed. This is the %d press since power cycle." msg.payload)

Does anyone know how to do this in Node-Red?

Thanks