Your company uses Azure DevOps.
Only users who have accounts in Azure Active Directory can access the Azure DevOps environment.
You need to ensure that only devices that are connected to the on-premises network can access the Azure DevOps environment.
What should you do?
Conditional Access is a capability of Azure Active Directory. With Conditional Access, you can implement automated access control decisions for accessing your cloud apps that are based on conditions.
Conditional Access policies are enforced after the first-factor authentication has been completed.