I have recently come across a plugin for Jgate database in GitHub (https://github.com/josille/ojs-plugins). I followed the given instructions and installed the plugin in the correct path. I do have crossref DOI prefix which is set in the system and DOIs are registered automatically. However, when I want to export XMLs through jgate plugin, the following message appears;
A valid DOI prefix must be specified in the Journal Setup in order to use this plugin.
Any solution would be highly appreciated.