To add a 1D barcode object to you page, just select the Linear barcode button from the Insert tab and click on a location on the page to place it. Now select the Symbology that you want to use from the drop down menu. All most common 1D Barcodes are supported.
Standard the Fixed value is selected, for using other values please see the "Using Standard Object Types" section
Of course a lot of extra options are available for the 1D Barcodes but they need to be access via the Properties window of the Designer. When the properties window is opened, select the Content tab.
You can add a checksum, set the options for specific barcodes like Codabar, Code-128, etc.