Although barcodes can not currently be generated within Intrakr, it's easy to create them yourself using MS Excel or MS Word.
Download Barcode Font
You can install a font on your computer, like any other font, that will render characters as a barcode that a reader will understand. We recommend this TrueType Font, which will generate Code39 1D type barcodes, which any basic reader should be able to pick up.
Fontspring does a good job describing how to install fonts on Mac and Windows.
Create Barcode Column in Spreadsheet
Create a new MS Excel spreadsheet with your product SKU/UPC in a single column. Then, create a new column with the following formula: ="*"&A1&CHAR(10)&"*"
Be sure to replace A1 with the cell that contains your product SKU. Copy and paste that new cell into all rows that contain a product.
Highlight all new barcode cells and change the font to the Code39 barcode font you previously installed. In the font list, it will likely look just like a barcode. You'll probably want to also increase the font size to about 72.