Disable Security Defaults while login into Power Platform / Dynamics 365

Security Defaults provides preconfigured security settings such as MFA – Multi-factor authentication for all users, blocking legacy authentication protocols, etc.

Any tenant created on or after 22^nd October 2019, will have this setting enabled for default.

An organization with complex security requirements could disable the security defaults and consider using Conditional Access instead.

Use Azure AD Conditional Access to block user access by device platform (Dynamics 365)

Use Azure AD Conditional Access to block access by country (Dynamics 365)

To disable Security default, login to Azure Portal

https://portal.azure.com

Navigate to Azure Active Directory > Properties

https://portal.azure.com/#blade/Microsoft_AAD_IAM/ActiveDirectoryMenuBlade/Properties

Toggle it to No and Save.

Hope it helps..