You can learn more about the free Autodesk Fusion 360 app for Xometry here: https://www.xometry.com/cad-add-in-for-autodesk-fusion-360/
Direct download links:
Windows: https://apps.autodesk.com/FUSION/en/Detail/Index?id=5430166430880711212&os=Win64&appLang=en
MacOS: https://apps.autodesk.com/FUSION/en/Detail/Index?id=5430166430880711212&os=Mac&appLang=en
Once downloaded, you need to accept a couple of T&Cs and the installer will add The Xometry Instant Quote App to your Fusion 360. Activate it through Tools > Add-Ins > Click the Xometry App > Check Run on Startup (optional) > Click Run