If you pre-ordered from the Vault you should have gotten a Steam key for the beta already (with a subject 'Your Dragon Commander Pre-Purchase on Larian Vault'). Check your spam folder, and see if it may have just been miss-filtered. If not, send an email to firstname.lastname@example.org, from your Lault email address, and request that they sent/resend you the key.
The rest of the pre-order stuff will be available when the game is released.
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