Call to a member function create() on null in leave_confirm_install()

Problem/Motivation

When we want to activate the module on config import we got the following error

30;43;1m[warning][39;49;22m Undefined variable $leave_confirm_storage leave_confirm.install:55
15:49:16   [37;41;1m[error][39;49;22m [37;41;1m Error: Call to a member function create() on null in leave_confirm_install() (line 55 of /var/app/web/modules/contrib/leave_confirm/leave_confirm.install) #0 [internal function]: leave_confirm_install()