How to set device password for spotify duo user (plan member)?

[easyuji]

I and my wife use Spotify Duo Plan.

Understanding to use spotify app on our Tesla car, we need device password.

I am main contract user and I have no issue to play Spotify on Tesla, however my wife can not create device password with the error message "there was a problem setting the password" as attached(password in screenshot has one character only for posting purpose here but we tried with more than 10 charactors password).

Is there any limitation for due member(plan member) to create device password ?

(She can access to device password web page by url I sent, but her UI do not show device password on the left side menu...)