Html extension on Premiere 2024

Hello everyone

I'm porting an old extension developed for ADOBE to premiere 2024;

but nevertheless I followed all the steps indicated
1. key in the registry
2. copy to the CEP\Extensions folder etc....

In Adobe premiere 2024 the extension does not appear to me, or rather... the window with the title appears but my HTML page inside does not load (simply Hello World)

my premiere version is

Adobe premiere PRO 2024 Version 24.3.0 (Build 59)

I also tried the example
https://github.com/Adobe-CEP/Samples/tree/master/PProPanel

but although the extension is seen from the extensions menu, in this case it doesn't even open.

Am I wrong about something? Am I missing some steps?

Thank you all for the kind replies.