If you use an Azure Cloud Service classic – which is probably the case if you use SCCM Current Branch and have deployed the Cloud Management Gateway (CMG), you will have to migrate your Azure Cloud Service from classic to ARM or to extended support before August 31, 2024

You can get all the details to migrate to extended support using this documentation https://docs.microsoft.com/en-us/azure/cloud-services-extended-support/in-place-migration-overview

NOTE if you have deployed SCCM Cloud Management Gateway, you can now migrate your CMG from classic deployment to ARM after you have upgraded your SCCM infrastructure to 2107 (see https://t.co/QeyJuqakbZ)