The simple way in VTPro is to add a "formatted text" item and click on the three little dots on the "label" field. It will open another window when you can choose an analog join and the format in which the analog value is to be represented.
Just reuse the same join the liquid gauge has.
You can also use a serial join and make something more complicated in Simpl, then transfer it in text format to the panel, but for 99% of the uses and the one you describe here, that shouldn't be needed.
