You was scammed, your are never required to trade items to verify registration for faceit. The link the scammer sent you was fake, this is how they got access to your steam account so they could redirect your trade to a different account.

Do the following steps to secure your account:
1. Scan for malware https://www.malwarebytes.com/
2. Check that the email and phone number on the Steam account are still yours.
3. Deauthorize all other devices https://store.steampowered.com/twofactor/manage
4. Change passwords from a trusted/clean device.
5. Generate new backup codes for your Mobile App https://store.steampowered.com/twofactor/manage
6. Revoke the API key https://gtm.steamproxy.vip/dev/apikey (there should be nothing in the APIKEY)


If the items you traded are for cs2 you can get them back via trade protect:

Steam Trade Protected Items
https://help.steampowered.com/en/faqs/view/365F-4BEE-2AE2-7BDD


For all other game items. unfortunately they can not be returned or restored:

Steam Item Restoration Policy
https://help.steampowered.com/en/faqs/view/3B6E-B322-2400-8D24

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