Typo3 12.1.3

Hi,
with Typo3 version 12.1.3
When uploading an extension i get a failure.

Extension bootstrap_package is not available
Extension site-package is not available

Any Clue ?
Best regards,
Hugo

My guess! Is its a nameing issue
Composer packages do not allow underscores
While typo3 extension keys do not allow dashes

So my-extension becomes my_package when the extension key is used. So you site package probably configured an invalid extension key in ext_emconf.php or composer.json