This article explains how to /month text after the price e.g. like this
You can edit the price field via Listivo Panel > Custom Fields > Edit “Price” field
Set “Text before value” and “Text after value” e.g. “/month”
You can also have multiple price fields e.g. one for full price, monthly rent, day rent, etc. You can add a new Price field this way:
It will be available on the submit listing etc.
You can also add it on search form same way as any other fields.