A developer creates an OmniScript to update billing information.

 An OS Action is the most efficient way to configure the action that invokes the OmniScript, as it allows the developer to reuse the same OmniScript across multiple FlexCards without creating separate actions for each one. A Custom Action is used to invoke a custom Apex class or Lightning web component. An OmniStudio Action is used to invoke an Integration Procedure or a Calculation Procedure. A Lightning Action is used to invoke a Lightning component or a Visualforce page.