Barcode printing - how to make the barcodes print more clearly - MAC

Go to https://heropackaging.com.au/pages/hero-printer-faqs and scroll all the way to the bottom.
Click the light grey text which says "Mac" under the heading "Tech Support Software"
This is a Google Drive link which should allow you to click a blue "Download" button. Click Download.
Google may display a warning, but please click "Download anyway"
A .dmg software file should download.
Click the file to start the installation process. You will then see a window looking like this:
Drag the "LabelRangePrinterTool" file across to the "Applications" folder.
The software should now be installed. Close that window and go to your Mac Launchpad and search for "Label".
Click the LabelRangePrinterTool software icon.
A warning box might display. Click Ok.
Then in the top left of your Mac, click the Apple icon > System Preferences > Security & Privacy
In the bottom right click "Open Anyway"
Click "Open"
You should then see this screen, where you can click the printer model HXD840-PRO, then click "Set Printer"
Change the "Darkness Setting" in the middle of the screen to 4.
Click the "Set" button at the bottom and the printer should beep once loudly.
Test printing your label file again and test different darkness settings until the barcode and label appears as needed.
Please note: these settings will permanently change the settings for your printer, and don't need to be done every time you print.