Hi @Ist126
For this issue, we suggest you could try to contact with your Global admin or Teams admin because this feature could be controlled by the Meeting Policies at the Teams admin center. Desktop sharing lets users present a screen or app during a meeting or chat.
Admins can configure screen sharing in Microsoft Teams to let users share an entire screen, an app, or a file.
You can refer to your admin this document and let your admin to recreate a new meeting policy and reassign to you, it shall take some time to take effect (maximum up to 24 hours)
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