HOW do I upgrade from High Sierra 10.13.6 to Mojave before losing support??? I cannot find any way to upgrade.

What model / year of Mac do you have?

Is it compatible with Mojave?

Mojave requires:

• MacBook (Early 2015 or newer)
• MacBook Air (Mid 2012 or newer)
• MacBook Pro (Mid 2012 or newer)
• Mac mini (Late 2012 or newer)
• iMac (Late 2012 or newer)
• iMac Pro (2017)
• Mac Pro (Late 2013; Mid 2010 and Mid 2012 models with recommended Metal-capable graphics cards)

If so, see here to download Mojave: link-> How to download macOS - Apple Support

Do note, High Sierra hasn't been supported for 2 years now. Last security update for it was released in November of 2020.

Also, this is a user to user forum, we users, are not taking away any support for anything.

See instructions in: How to download macOS - Apple Support

Also, you may want to consider upgrading to a more current version than Mojave if your Mac will support it.