You can enable or disable automatic push requests. From the Duo Prompt screen, click the My Settings & Devices link on the left-hand side:
Then, choose an authentication method and complete two-factor authentication. Click the When I log in drop-down menu and select Automatically send this device a Duo Push if you want to enable an automatic push upon logging in or select Ask me to choose an authentication method if you want to leave the automatic Duo Push off:
To exit My Settings & Devices, click the Back to login or click the UWM logo on the left.