You can file online (a state filing fee for online filings is $50) at the Missouri Secretary of State's portal or by mail (paper filings cost $105). Create an online account on the site and complete the form right on the site, i.e. fill out the required fields located under "Create an LLC." Alternatively, you can download a PDF copy of the Certificate from the site, enter the required information in it, and send it to the Divisions Corporations for review and approval.