Shiptheory's Pick Pack Ship feature now has the functionality to print to your desired printer when using. To do this, you'll first need to ensure you have the Shiptheory Print Client installed and working on the PC connected to your desired printer(s). Please see a guide here (for Windows) or here (for Mac) that goes through the Print Client setup in some more detail.
Once that is set up and ready to go, the next step will be configuring Pick Pack Ship to send to that printer when using. To do this, you'll first need to be on the Pick Pack Ship page here. You'll then need to access the "Advanced Settings", which can be found by clicking the option in the bottom left of the page:
From there, you'll then want to scroll down to "Printer Selection", and ensure that setting is changes to "Yes":
You'll want to ensure you hit "Save" after this, and then refresh the page. After you've done that, you can then select a printer to use for the orders you are going to put through the page:
If you have any questions from there, or have some issues doing this, please feel free to contact Support.