mcli has three different modes for issuing commands:

• credential - Credential Mode provides access to the account and key commands used to manage user accounts and nodeKeys respective. Learn more about Credential Management.
• net - Network Mode is for creating and managing Marconi networks. Learn more about Network Management.
• process - Process Mode which is for launching and stopping Marconi components

Type j and the name of the mode you want to switch to.

Launch mcli and jump to Credential Mode to create an account

$ mcli -console
> j credential
> account create