Before you start, please make sure that you have a Site backup of your SCCM Server. You can take the back of the server by going to Administration \ Site Configuration on the Right side panel, select your Site. On the Ribbon on top Select Site Maintenance.
Open the SCCM console
Go to Administration \ Updates and Servicing
In the State column, ensure that the update Configuration Manager 1810 is Available
You can use the query to find out all devices which are not update to latest client version 5.00.8740.1012