How to save data upload parameters. I'm uploading data from a website daily.

Hello again Tilly01Hill ,

Thanks for sharing the screenshots they really help clarify what is happening. The repeated Anonymous credential prompt is occurring because Power BI treats every variation of the URL as a completely separate data source, which means the service will not retain the saved authentication if the address changes. You can safely ignore that credential window once the base URL is set, because the parameter should be handled inside your query rather than in that pop-up.

The most reliable way to keep things stable is to leave the base address fixed and pass only the changing date as a parameter in your M code. Power Query is fine with dynamic elements as long as the host itself stays the same, and following this pattern will allow the Anonymous credential to persist so you are not asked to authenticate every day. You can simply update the parameter in the Manage Parameters window or have your query generate the date automatically. There is no need to re-enter anything in the Access Web Content dialog or recreate the connection referencing the parameter directly in Web.

Contents is all that is required. This approach keeps your credentials intact, avoids URL changes that break the connection, and makes your daily refresh process run smoothly without any extra steps.

For more detail, the Microsoft Learn articles on the Power Query Web connector and on Web.Contents provide helpful guidance:
Web.Contents - PowerQuery M | Microsoft Learn
Power Query Web connector - Power Query | Microsoft Learn

Thank you.