Numbers download for high sierra

Hello everybody, sorry if my english will be not perfect but i'm italian.

I made a clean installation to Mac OS X High Sierra and i've lost my iWork version in my early 2009 iMac where i'd installed a new SSD.

Before i was used to use Mac OS X El Capitan

I tried to install the latest compatible version of Numbers into the Apple Store using the Shopping tab , but i can only download 2.3 Numbers version.

My old Numbers files were located in Dropbox and using this version of Numbers i can't open those files because it says <document "index.xml" is not present>.

I Think it's because i need to download a different version of numbers but at the moment i can't do it.

When i was downloading it in Apple Store the downloading system said "you can't download last version of Numbers because you need 10.14 Mac OS X version, would you download last compatible version of Numbers?"

I said "yes, that's perfect, finally!!!", but then i've got only 2.3 version.

Thx for reading my question, and thank you if you'll try to help me.

Sorry again if my english was not clear.