Giveaway my own asset

Is there any method to giveaway my own asset to some friends or as a price of a contest?

You can email Epic and give entitlements to your assets, you just need to provide Epic with the email they use for the Unreal launcher account.

If that doesn’t work, then why not post it in Community Tools?

Also if its related to another community project you can simply add it, and fork on github.