Stop the agent job

SET NOCOUNT ON

DECLARE @returnTable TABLE ([i] INT)

DECLARE @ReturnCode INT = 1

INSERT INTO @returnTable

EXEC sp_executesql

    @statement = N'EXEC @ReturnCode = msdb.dbo.sp_stop_job N''IndexOptimize - USER_DATABASES''',

    @params = N'@ReturnCode INT OUTPUT',

    @ReturnCode = @ReturnCode OUTPUT

IF @ReturnCode = 0 --success

    PRINT 'job stopped successfully'

ELSE IF @ReturnCode = 1 --failure

    PRINT 'job did not run'