Am i allowed to do an Epic Game Store key giveaway on steamgifts?

No it's called steamgifts for a reason, steam keys only.

I'm pretty sure you can, but you'll have to avoid the official giveaway functionality, which is to be used only with steam key or gifts.
You might organize a raffle in the forum or just do a random drop, for instance.
The guidelines thread may also help you.

I think you can't - this is the information on the help section of this website:

When creating a giveaway you have the option to choose either "Gift" or "Key". The two are interchangeable, and after your giveaway ends, you can add or remove keys regardless of the option you select when creating your giveaway.

Gift
You'll want to choose this option when you plan to send a Steam gift to your winner, or if you would like to add keys to your giveaway after it ends. Once your giveaway is complete, you'll be able to see the winner, along with their email address. You can then choose to either send the winner an email, or a message on Steam to deliver your gift.

Key
If you choose this option, you will be required to enter one or more Steam keys when creating your giveaway. Once your giveaway is complete, you'll be able to see your winner, along with their email address. You'll notice the key you previously entered is displayed next to their username, along with buttons to modify or delete the key if necessary. At that point, the key will not yet be visible to the winner. They will only be able to see the key on our site when you check the "Send Key" checkbox.

I think it says that there's no room for non-Steam gifts or keys here.. once I mistakenly bought a GOG key months ago and I gifted on a group I'm in on Steam in order not to make mix-ups here, since it was redeemable only on GOG =P
Plus, you're entitled not to remove the game on your Steam account so, if someone wins and activates a key on another website, it would most likely result as not redeemed on Steam..

You could but only if you are ready for the winner to marks it as not received, cause otherwise it will look like he has not activated his win.
That means you will get no cv from that giveaway as well and you will loose a giveaway slot

I would definitely be against making it a public giveaway, most of the entrants wouldn't even read the description even if you state that it is for Epic and you will delete the GA afterwards
Maybe an invite only giveaway after a very easy puzzle, making a group for it, or whitelist one - but in all case you have to delete the giveaway afterwards, and using SG only as an entry + RNG system. It's still stretching the rules a bit, but at least with deleting it afterwards you keep stats intact..

You kinda could do a topic where you say you give it away, and use random.org to get a random commenter win it - this one is 100% allowed.

ok thanks for the advice everyone, i'm glad i asked first
i'll come up with a fun way to give it away in the forums then instead

Epic keys will be in humble soon ..... the future is here ! Evolve and adapt.

can't be done because epic is trash and we can't check what's in people's libraries (no check = no way to confirm winners activate keys).

"because epic is trash"

-1. It is not trash. Great free games/giveaways there

"can't be done because we can't check what's in people's libraries (no check = no way to confirm winners activate keys)."

+-0. Because playnite client already does read the installed/owned epic games, so this maybe possible in the future for steamgifts!

Total = -1

You can't create a giveaway, because the site is not integrated with Epic's library to check the activation of the gift. If you want you could just give it away in the discussions section, but then again you can do the same on reddit or other internet forums.

You can't. Same goes with u(don't)Play keys, GOG keys, etc...

While you can't actually create a giveaway via the giveaway system here on SG if you wanted to give away the game here on the forums that would be fine.

As Melliuc said above

All giveaways should be for Steam redeemable gifts or Steam redeemable keys.

That's all you need to know.

burn the witch

You can for example create raffle on forums/discussions, but this won't give you any points to your SG profile.
That said it would be great if it was possible to integrate other platforms (gog, epic etc.) to steamgifts but as i understand it is technically not possible or would be hard to do.