This is a text book type of scam. You can do 2 things
1) Call out they are a scammer and they unfriend you (ending the scam)
2) Go on with their little stupid text book scam
Lets say you went with the fun choice (A.k.a the 2'nd one) and they ask you to add a "Steam admin" on Discord or Steam. It doesnt matter which one it is but, DONT CLICK ANY LINKS OR ACCEPT TRADES because they will;
A) Steal ur information and ur steam account
B) They will steal ALL of ur items and send it to their main account
As an example photo I saw

This is a text book scam too. But in this they send a "real screenshot" of "their" purchase history, but they added "WHO" or "WITH" part. If you check ur purchase history you can see theres no "WHO" part. Also its STEAMS fault not yours.
Here are more photo's of this scam that happened to me
This isnt mine BUT heres the picture with the "WHO" part

This actually is kinda boring, You can literally get their ip by just using "grabify" I am not saying you SHOULD im just giving yall a little bonus tip.
Anyways this one is actually kinda rare. Heres some more photo's
Also YES, thats a real site. So please, dont try to join it.

Ok so these type of scams have LOTS of huge red flags. Let me present it with this Scammers one!
1) Privated inventory but still has the real persons inventory id on their account
2) Low play time but "LOTS of items"
3) Why would a "big trader" go for a random person
And more but because theres no subway surfers, family guy or those mobile game videos on this ♥♥♥♥ I wont make you die out of boredom.

So people try to scam you by saying "Oh, so my friend got scammed by someone that looks like you. And bla bla group has the same issue and I know you are not the guy. So please tell the admin you are not a scammer bla bla bla" so. You add the group admin, and they say "oh go and uhm.. send us your TRADING link so we can check the reports and bla bla bla" dont do this. They are just tryna scam yall. Just try to waste their time as much as possible, Like go to the end of their scam and decline the trades or smt. Heres some examples

1) Never add random people you never saw in game
2) If they accidentally did something, They did it knowingly.
3) No big trader or someone like that will go for a person that has low items
4)Steam admins wont add you, they will talk thru TICKETS
5) If they send a "video" of them with the picture below, ask them "nicely" to VAC ban you