Click the person icon (bottom-right) to instantly sign in as a test account — see your studio from every role without logging out.
Bottom-right of every screen (owner / manager with Settings permission). Click to open a panel with all test accounts in your studio.
You're instantly signed in as them. An orange banner stays at the top: "Viewing as {name} — Return to your account." One click returns you to your owner account.
Test account credentials are also listed on Settings → Test Accounts (with copy buttons), in case you want to log in with them in another browser.