I am trying to submit my file and it won't let me hit the "confirm payment" button. Is this because the Missouri state return still needs to process?

Maybe you are waiting for some forms.  Click Review to see if you are missing some forms needed in order to e-file.

 

Many federal and state forms are not yet available.  Check here for form availability. The dates are subject to change.

 

Tax form availability tool,

 

No hurry to e-file since the IRS will not begin to accept/reject 2023 e-files until January 29.