my mac is not compatible with catalina, I need to download high sierra but cant find it in the app store.

See if you can upgrade to 10.11, 10.12, 10.13, see sys requirements...

https://support.apple.com/en-us/HT206886

https://itunes.apple.com/app/os-x-el-capitan/id1147835434?ls=1&mt=12

https://support.apple.com/kb/sp742?locale=en_US

https://itunes.apple.com/us/app/macos-sierra/id1127487414?ls=1&mt=12

https://support.apple.com/kb/sp765?locale=en_US

https://itunes.apple.com/app/macos-high-sierra/id1246284741?mt=12

You should be able to get High Sierra from this link to the App Store:

https://itunes.apple.com/us/app/mhttps://support.apple.com/en-us/HT208969

(The link is on this Apple Support page - How to Upgrade to macOS High Sierra: https://support.apple.com/en-us/HT208969 - scroll down to section 4)

Note: this downloads the High Sierra installer app to your Applications folder. Once you run the installer and High Sierra is finished installing, the installer app is erased. If you want to keep a copy of the installer for future use, just copy it to another folder. But keep the original in your Applications folder - that's where it needs to be when you run it.

Once High Sierra is installed, all the necessary High Sierra updates & security updates should appear on your App Store Updates page; if not, you can get them from Apple Support Downloads: https://support.apple.com/en_CA/downloads/high-sierra (But unfortunately you can't get the High Sierra installer there, only the updates.)

Try it again.

I tested it before I posted my original reply (above). After you get to the page entitled How to upgrade to macOS High Sierra, scroll down to item #4 where it says If you still need macOS High Sierra, use this App Store link: Get macOS High Sierra. Clicking that link takes you to the app store where you can download High Sierra.

I tested it again right now and it works fine.

Sometimes the system does not allow downloading high sierra from the app store.

Therefore, I offer you a terminal command that I have currently tried and that allows you to download MacOS high sierra from the App store.

open macappstores://apps.apple.com/us/app/macos-high-sierra/

The High Sierra instructions...

http://osxdaily.com/2017/09/27/download-complete-macos-high-sierra-installer/

Naw, it's just that you have an old copy already in Applications, there are 2 cures...

Disconnect from the Internet & set the Date back to 2014, then you can run the Install MacsOS High Sierra App in Applications, so expired Certificates are not expired.

Or... trash the Install MacsOS High Sierra.app in Applications then a new copy can be downloaded.

So this link doesn't work for you? It does here...

https://apps.apple.com/us/app/macos-high-sierra/id1246284741?ls=1&mt=12

What year/model Mac? What OS is running now?

How'd it go?

the itunes link to download HIGH SIERRA is not available :-(

It redirects to iTunes App Store. Once there the message box says: Item not available. The item you have requested is not available in the United States sore.

I am in Canada.

Whew!?

What exact Mac do you have?

macbook pro 17" early 2011 A1297 (that is why I need High Sierra)

This link leads to a High Sierra that is damaged and won't download...