Before you can use NDI with Teams, you need to enable NDI streaming within the Teams Admin Center. To do this, navigate to Meetings>Meeting Policies, then select the relevant meeting policy assigned to users you want to use NDI. For example, if you want all users to use NDI, update the Global (Org-wide default).
Within the policy itself, scroll down to the Audio & video section and then switch Allow NDI streaming to On:
After saving the policy, wait several hours before closing and re-launching Teams to ensure the new setting has had time to apply.
NDI is not enabled by default in Microsoft Teams. You should enable it and disable it when you want to use it because when it is enabled, other machines on the LAN can potentially capture the meeting.
To enable NDI in the Teams client, open your Teams settings and select Permissions. You will see a new option to enable NDI, as shown below:
After enabling NDI in Teams, all meetings that you join will have streams available via NDI over your local network. When you join a meeting in the Teams desktop app, you will be notified that broadcasting capabilities are turned on.