If your component is not available within the sidebar browser, it may be due to the availability of the component being restricted to certain entity types.
You can update the availability of your component when editing your component, clicking the 'Availability' accordion and then changing 'Available on entity type' drop-down to the entity you want your component to be available too.
To find out more about this functionality, check out our user guide.
The component may also not be appearing in the sidebar browser if you have 'Enable selection' unticked. This will prevent page editors from using that component on a node.