I need to download MacOs 10.13. Help me. I can't find anywhere

Thanks for reaching out here in Apple Support Communities ramiro40. We're happy to assist.

If you have hardware that is not compatible with later versions of macOS, you might be able to install macOS High Sierra. Take a look at the article below. There is a direct link that may help under "Download macOS High Sierra."

How to upgrade to macOS High Sierra

Regards.

Don't use Firefox for this link...

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

If you get a corrupted message...

Naw, not damaged, 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 more recent version can be downloaded.