Can't upgrade to Mac OS Sonoma from Mac OS High Sierra

I suppose you mean that you can't download Sonoma.

What mac do you have, exactly? If in doubt: from the Apple menu, choose About this Mac. Tell us what it says Specifically about model and year - eg. Macbook Pro (13", late 2015) or similar.

AFAIK, there is no single mac model that can run High Sierra and can also run Sonoma.

Not Possible - Full Stop

macOS High Sierra - Technical Specifications

• MacBook (Late 2009 or newer)
• MacBook Pro (Mid 2010 or newer)
• MacBook Air (Late 2010 or newer)
• Mac mini (Mid 2010 or newer)
• iMac (Late 2009 or newer)
• Mac Pro (Mid 2010 or newer)

macOS Sequoia is compatible with these computers

dialabrain wrote:

macOS Sonoma requires one of these Macs: macOS Sonoma is compatible with these computers - Apple Support

macOS Sequoia is compatible with these computers

Thank you for the confirmation

dialabrain wrote:

PRP_53 wrote:

Thank you for the confirmation

It wasn't a confirmation, it was a correction. You posted the link for Sequoia. The user asked about upgrading to Sonoma.

Correction, the computer in Question does not qualify for either or Sonoma nor Sequoia

The OP's tag line says that they have a 13" MacBook Pro running High Sierra.

If that Mac has a hardware model year of 2018, it can run Sonoma and Sequoia. Any other 13" MacBook Pro that is compatible with High Sierra is too old to update to either one.

macOS Sonoma requires one of these Macs: macOS Sonoma is compatible with these computers - Apple Support

PRP_53 wrote:

Thank you for the confirmation

It wasn't a confirmation, it was a correction. You posted the link for Sequoia. The user asked about upgrading to Sonoma.

PRP_53 wrote:

Correction, the computer in Question does not qualify for either or Sonoma nor Sequoia

That's not a correction. No one said it did. Are you done yet?