To add custom fields in the property custom template follow the below steps:
Add or edit the page used for custom property template
Add the shortcode Property Page Only-Test with Details Settings
The shortcode has the functionality to not display the field on front end if it is not filled but for this option to work correctly, the fields need to be added separately. A new shortcode for each field.
With Bakery editor
In the shortcode, you will have the list with all fields and you will need to add in text section to code for the ones that you wish to display.