Hi guys , only made this account to sell Song of Nunu: A League of Legends Story game code that I bought the collection from Riot store ...and instead of choose steam I accident put GOG , I can sell the code so please if anyone want it so i can buy the game on steam . please tell so i can share my paypal

Well, that's one heck of a user error...
How could you not notice the wrong choice before checkout?
They even ask you to check a box, that you understand that the game code is non-refundable and non-exchangeable - BEFORE you can proceed to checkout...didn't you double-check, before setting that checkmark?

Almost all shops just sell Steam codes, especially those shops noone has ever heard of.

This is the in-house store of Riot Games (League of Legends, etc).
Besides Steam keys, they also sell GOG keys, Epic keys and Switch keys.
As you can see in my screenshot.

People don't read, they just click "Next", "I agree", "You can have my soul and my firstborn".

Yep. Absolutely.
A huge problem nowadays.
In this example, the OP literally had to confirm "The game region and platform I need are selected". smh

Oh no... The Nunu Plush Hat is sold out.

What the heck is a "Nunu Plush Hat" in your attachment? Is that a hidden DLC for the game or is it some bonus within LOL?
[Edit01] Oh is it physical? I'm so not used to seeing GOG keys being offered for Collector's Editions that I never even considered it could be physical lol. Always read the terms and conditions.

I enjoy reading; But when there's 100 pages of legalize no one has time for that bs. And even if you did, you still want it and have to hit okay anyways.

Think it's safe to say, no one accepts the license of anything they use anymore and won't abide by it. I certainly don't.

Well sure, but in this case, it was one of 4 buttons and a 19 word sentence.

alright

I'll agree that it's impossible to read every long legal mumbo-jumbo that comes with even the smallest thing you do on the internet.

and you don't help at all , only sitting you ass typing without being useful , if you don't know I did put steam but i guess Riot site still have the bug where your account and your items reset of what you choose also your shop region changed due the bug , so that's why i tried to contact them .

Wow, my comment really bugs you, huh?
I mean, two responses already - to a post that you consider "not helpful at all"...

Truth hurts.

Last time I looked, it is not allowed to sell codes here.