You’ll need to use what’s known as the ‘internal value’ for the property. These are highly specific to each property, as the ability to edit these internal values within HubSpot has evolved over time and is now totally prohibited.
That being said, the general syntax replaces spaces and most other special characters with the underscore character (‘_’) -- as shown in your example #3.
Best way to be certain what the internal value for any given property is is to view the property within the HubSpot UI. Once in the property definition dialog you’ll want to click on the ’
</>
’ symbol to reveal the internal value.
- see image
HubSpot Properties Internal Values