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After you enter in your password, DUO will send your phone a notification for a DUO Push. Click on the notification.
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Click approve in the DUO app.
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After clicking approve, it will navigate back to the Teams/Outlook app, and it will let you know that it is successful. It may also ask you to trust the browser, click yes trust this browser.
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You have successfully Duo 2-factor authenticated and Outlook\Teams will finish signing you in.
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