Does Lastpass have a requirement on the length of the master password? Documentation says they recommend 12 characters as minimum, which seems short. Wondering

Does Lastpass have a requirement on the length of the master password? Documentation says they recommend 12 characters as minimum, which seems short. Wondering if its enforced or if it's possible to have "password123" as master password? Also, sounds like URL leaked in clear text - so targeted attacks will be very likely. This is quite bad with long running implications.