Wix.com?

A good day, dear,

see here:

https://support.wix.com/de/article/wix-editor-one-determined-page-with-one-passwort-sch%C3%BCtzen

To protect a page with a password:

1. Click on the left side of the editor on Pages & Menu
2. Next to the corresponding page, click the icon for further actions
3. Click Settings.
4. Click the permissions tab.
5. Select password holders.
6. Enter the password you selected for the page.
7. Press Enter button on your keyboard.

Best regards