How to Execute Vim Command to Delete All Empty Lines in VSCode and VSCodeVim?

I'm using VSCode and the VSCodeVim plugin. I'm attempting to create a key mapping to delete all empty lines in a file, but I'm encountering issues.

Here's the code snippet that I've added to my VSCode configuration:

{"before": ["<Leader>", "q"],"after": [],"commands": [    {"command": ":s/^\\s*\\n//g<Enter>","args": []    }  ]}

When I use the above configuration, I get a "trailing spaces" error. If I remove the Enter from the command, it gets posted to the command line but doesn't get executed. Pressing colon afterwards deletes the command. I have also not been able to switch focus over to the command line without deleting the current contents.