If this is your case, you'll need to create an app password before continuing with these steps - You can do this with the steps mentioned below. Important: This option is not available if two-step verification is enabled on your account.Turn on the Allow apps that use less secure sign in toggle switch. On the top-right, click the menu (gear) button, and select Account Info. Sign in to your Yahoo Mail account using your web browser.If you have installed the desktop version of Outlook 2016 on your device, you can quickly set up and manage your Yahoo email account using the following steps:
How to set up a Yahoo Mail account on the Outlook desktop app