gmail calendar api keeps my password

I'm using my private gmail calendar in Thunderbird and I don't want it to be available if I don't type in my password at the startup of Thunderbird, as some other users can access my computer. Since a recent update of Thunderbird this was the case (asking me my gmail password, but recently an api popped up asking me to login at gmail but Thunderbird retained this information). Every time I start Thunderbird my calendar is available to anybody. I removed the calendar, restarted Thunderbird and made a new calendar but my password is still present in Thunderbird, how can I remove this (my gmail password)? How can I have a request for password, for my calendar, each time I start Thunderbird (without changing my gmail password) and as it used to do.