Enable remember Multi-Factor Authentication
1. Sign in to the Azure portal.
2. On the left, select Azure Active Directory > Users.
3. Select Multi-Factor Authentication.
4. Under Multi-Factor Authentication, select service settings.
5. On the Service Settings page, manage remember multi-factor authentication, select the Allow users to remember multi-factor authentication on devices they trust option.
6. Set the number of days to allow trusted devices to bypass two-step verification. The default is
14 days.
7. Select Save.
References:
https://docs.microsoft.com/en-us/azure/active-directory/authentication/howto-mfa-mfasettings