I just want mods nothing else.
If Kinguin sold you a partial product, the best thing to try is to contact their support and see if you can get a refund, or a version that actually gives you the complete product.
Early access to the game is only officially sold on Steam and on Humble Bundle. The complete product comes with the SPF key. If you get it from any other reseller, and there is an issue with the key you got (or missing keys), then contacting their support is your best option.
We will of course offer you support if you purchase from one of the official outlets, or have been gifted the entire product. We don't have a way to generate an SPF key that isn't attached to the purchase of the whole product, can't offer key recovery for an account that isn't yours. So, gotta contact Kinguin support.
We do plan on adding Steam workshop support in the future, if that helps.