Missouri sports betting will go live on Dec. 1, but users there can pre-register at BetMGM starting on Nov. 17. The BetMGM bonus code POSTBET will access up to $1,600 in bonus value on launch day by way of a first bet on the house and an extra $100 for pre-registering. This value can be used toward betting anything, including the Chiefs as they chase a playoff berth, the Blues in a lackluster season or any other Missouri-based franchise. How to pre-register for BetMGM in Missouri Select your