Within Teamwork Chat, you can reset your password via the web version of the app.
On the login screen, select Forgot password from the password field.
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You will then be prompted to enter an email address to receive your password reset on.
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Once the email has been received, click the link as directed by the email. You will then be prompted to create a new password for your account.
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Note: Changing your password from Teamwork Chat will also update the password for all Teamwork products associated with that account.
For more information see: Accessing Your Teamwork Chat Site