Microsoft Entra ID Permissions

In the navigation pane to the left, click API permissions.

In the opened pane, select the Yammer API.

Click Delegated permissions, add the following permission: Other permissions: user_impersonation, and click Add permissions.

Click \+ Add a permission and select SharePoint API with Application permissions. Add the Sites:Sites.Read.All permission and click Add permission:

Grant all the above-mentioned permissions.