At home our ebikes are in our 'toy barn', a separate 3 car garage full of boats, bikes, etc.
Our homeowners policy covers them here and where we travel. There is the policy deductible and rapid deprecation as we found out when an expensive bike our son took to college was stolen. But he was happy with the check.
For in town errands I usually use the frame mounted Abus 'cafe' lock and its matching cable to secure the bike for a few minutes. For longer stops and for out of town travel I use the 'cafe' lock with an Abus folding lock. I always try to secure the bike frame to something stout and fixed so it can't just be carried away. The wheels and seat post need hex wrenches to remove so I usually just include the rear wheel in the 'lockup'.