Is it possible to secure a form using a password?

Bonjour;

je vue sécurisé un forme par un mot de passe est un nom de utilisateur est j'arrive pas a le faire. merci de m'aider pour le faire

As I can understand, you need to protect your forms with username and password. Please note that it's not possible to do that, although there is a workaround you cannot use words such as username, password, login or the like, otherwise your account can be suspended due to violation of our terms, even if you're not using your forms for phishing purposes, but it's not allowed to ask for any kind of sensitive data. 

You may however use different words and hide your fields, then if the correct word is typed the fields on your form will be displayed. 

You will find more details about the show/hide feature on this guide: https://www.jotform.com/help/316-How-to-Show-or-Hide-Fields-Base-on-User-s-Answer 

I hope this helps.