Sync os iPhone 12 with IOS17 with a MacBook with MacOS El Capitan

Hello,

I just updated my iPhone 12 with IOS17 (I updated also the iPad) and now iTunes doesn’t recognize it. I am using a Mac Book Pro Mid 2009 running OS X El Capitan 10.11.6, running iTunes 12.8.2.3.

I am requested to install a software update, I click on « install », the download starts, then I get a message that the installation failed because « the the software is not currently available on the updates server ».

All devices have the latest updates possible installed. When connecting the phone by cable with the MacBook Pro, Photos.app opens and I am able to see the pictures. But when opening iTunes the phone icon doesn't appear. and I am unable to access the device, neither to copy music, etc.

Whats could be the issue here?

Thanks!