You can enable Xbox One/Series X/Series S Dev mode for free to sideload UWP:
https://learn.microsoft.com/en-us/windows/uwp/xbox-apps/devk...
https://www.techrepublic.com/article/xbox-series-s-and-x-dev...
https://learn.microsoft.com/en-us/windows/uwp/xbox-apps/devk...
https://www.techrepublic.com/article/xbox-series-s-and-x-dev...
Individual accounts cost approximately $19 USD, and company accounts cost approximately $99 USD (the exact amounts may vary depending on your country or region). This is a one-time registration fee and no renewal is required.