If you are doing anything non-trivial with ZAP from the command line then you should use the Automation Framework. This has direct support for scripts.
If you cannot use the Automation Framework for any reason then you’ll need to use the following command line options (with the values changed to match your requirements of course;)
-config script.scripts.name="Remove Strict-Transport-Security"
-config script.scripts.engine="Mozilla Zest"
-config script.scripts.type=proxy
-config script.scripts.enabled=true
-config script.scripts.file="/home/user/scripts/Remove Strict-Transport-Security.zst"
See also the FAQ: How do you find out what key to use to set a config value on the command line?