As said before, you can combine usability testing user interviews and optimize time with the same user; the ideal time would be between 45 and 60 minutes.
Pro tip: test the script prepared in advance. Although you don't need to strictly follow the script, you will want to make sure you know the purpose of the test and what questions you want to have answered. Ask the users to give their first impressions on entering the site, app, or using a service or product. If they have already used or had previous experience with your site, app, product, or service, ask where they usually navigate and what they usually do. Let them be the expert by explaining to you how to do or use it.
Even before starting the test, remind the user that they are not being tested and that their participation aims to improve the navigation of the product, app, or product and...
