Current process:

Place cursor. Take hands off keyboard. Click the icon. Put hands back on the keyboard. Paste in the URL. Press return (hooray!) to "Look up" the citation. Take hands off keyboard. Click "Insert".

Desired process:

Place cursor. Take hands off keyboard (*grumble*). Click the icon. Put hands back on the keyboard. Paste in the URL. Press Return (hooray!) to "Look up" the citation. Press Return to "Insert" it.