It helps if you actually read the responses people make in a thread. Here’s the answer to your question, pasted from the post DIRECTLY above yours.
Just follow this chain: Orders > Click on order you want to ship > Click “Create shipping label” > Select shipping service > Click “Buy 1 shipping label” > After page loads look directly above the “Print shipping label” button and you should see a sentence “Change format: 8x11”, click it and select 4x6. Now your labels will print correctly on your label printer (assuming you select the correct settings in the print panel).