after i create a survey,

i  use Send private invitation to your audience (only one response per recipient and per invitation).

ok, now the receiver get a link to my odoo page what looks like:

http://erp.salamander.zone/survey/start/assessment-of-satisfaction-dissatisfaction-4/90b0edbd-6748-403e-9d78-2b2768d34d27

but after the receiver click on it 

he gets a Not Found - The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.

if the user login in before than i can follow up the survey.

i know there is a public web link to your audience, but i need to track the email/user for special surveys

unfortunally i don't find any documentations or some more expressive explanations