Hi Peter,
The source code for Blazor UI components can be downloaded from Telerik.com if you have a license.
To do this, log in to your Telerik account at Home | Your Account (telerik.com). Select Downloads and then search for the UI for Blazor product. With the product selected scroll down until you see the Source Code section.
I hope this helps.
Regards,
Justin
Progress Telerik
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