It's been brought to our attention that Joplin server has a personal/non-commercial license. Please see https://discourse.joplinapp.org/t/crowdfunding-joplin-server-license/19891 for more information. To that end, I have already pushed a change in the package highlighting the license.
Just wanted to give a heads up that you should not be already using this for Commercial use. Doing so will be in violation of the upstream license.
You can read the full license here.