Hi, I used a translation service to read your comment, so there may be some misunderstanding. The reason Keywi uses a password for Secure Storage is explained in more detail here https://github.com/LEDfan/keywi#usage and here (with some tips to make it easier) https://github.com/LEDfan/keywi/issues/106 . Note that there is an option in the addon preferences so that Keywi won't ask your password every time at the startup of firefox, but only when using Keywi to fill in a password.
If you have any further issues or questions, please open an issue here (in English please :) ): https://github.com/LEDfan/keywi/issues/new