If you ever need to impersonate (login as) a user in your Joomla! website, you're in luck! This component allows you to easily switch to another user's account and see what they see. This can be very useful for debugging, testing, or providing customer support. To use this feature, you just need to navigate to the component in the back end, find your use in the familiar Users view with all necessary filters, and press button "Impersonate".
How to use (Video)
Read more https://extensions.joomla.org/browse/new/extension/access-a-security/ph-impersonate-login-as