Do not create references or in-text citations for whole websites.
To mention a website in general, and not any particular information on that site, provide the name of the website in the text and include the URL in parentheses. For example, you might mention that you used a website to create a survey.
We created our survey using Qualtrics (https://www.qualtrics.com).
If you are writing online, you can link the name of the site directly so that the link has descriptive text.
We created our survey using Qualtrics.