https://docs.wp-property-hive.com/article/594-customising-the-add-to-shortlist-button-label
Customising the 'Add to shortlist' button label - Property Hive Documentation
If you wish to rename the 'Add to shortlist' and 'Remove from shortlist' button label, you can do so in one of two ways: Option 1: Using the Template Assistant
add to shortlistbutton labelcustomisingpropertyhive