Ensure you've installed the latest version of the DYMO LabelWriter Software (8.7). You can download it via:

After installing the software, you need to restart your computer, plug in the printer via USB and make sure it’s powered on.

You can check if the DYMO Web Service is running by going to the following web address in your browser: https://127.0.0.1:41951/DYMO/DLS/Printing/Check.

If your web-service is running, you should see a success message like the one below.

Ensure you've installed the latest version of the DYMO Connect. You can download it via:

After installing the software, you need to restart your computer, plug in the printer via USB and make sure it’s powered on.