If you know the url to your app catalog or are using a site collection app catalog, you can skip to step 6.

  1. Login to your Office 365 admin center page with an administrator account;

  2. Open the app launcher and click on Admin;

    admin.png

  3. Open your SharePoint Admin Center;

    asd

    If you can’t find the apps button, look for add-ins.

  4. On the left pane, click on apps and then App Catalog;

    catalogue.PNG

  5. Inside, on the left pane, click on Apps for SharePoint;

    asd

  6. Now click on Upload and upload the .sppkg file that's inside the spfx folder in your web part package. Replace the file if prompted;

    upload.PNG

  7. Deploy the solution once again.

    trust.PNG

And that's it! Your web part is now upgraded. ✅