Is it possible to open a new tab in a specific container when using Firefox Containers?
Is there a command-line option to do this?
An extension is currently required to make this work…
Install the open-url-in-container extension. It's a rather simple extension and works very well. It is open-source with all of its code on GitHub: honsiorovskyi/open-url-in-container
Now, you can use URIs of the form ext+container:name=${CONTAINER_NAME}&url=${ORIGINAL_URI} to open an arbitrary URI in an arbitrarily-named container. Works via command-line invocation, entering them in the location bar, or links from other pages.