1. Click on the container and click 'Edit'
2. In the Update Container window, go to the bottom and click '+ Add another Path, Port, Variable...'
3. In the Add Configuration window that pops up, change Config Type to variable, set the name and key to 'COUCHDB_USER' and the value to your username. Click Add.
4. Repeat step 3 for COUCHDB_PASSWORD.
5. Click Apply