Tap the menu icon in the top corner of your screen, then select Saved Locations.
Tap on a list to select it.
Tap the three dots at the top and select Send a copy.
You’ll see your sharing options. Select the app you’d like to use, or copy and paste the link.
Once your contact(s) receive the link, they will only be able to save a copy to their own account, but will not see any updates you make to the original list.