Computer Configuration > Administrative Templates > Microsoft Edge - Default Settings (users can override)
Both
HKLM\Software\Policies\Microsoft\Edge\Recommended
Allow the use of your organization's branding assets from Entra, if any, on the profile-related UI of a profile that's signed in with an Entra ID (formerly known as Azure Active Directory) account. This requires a browser restart to take effect. If you enable this policy, your organization's branding assets from Entra will be used. If you disable or don't configure this policy, your organization's branding assets from Entra won't be used. For more information about configuring your organization's branding assets on Entra, please visit https://go.microsoft.com/fwlink/?linkid=2254514.