Missing Doi Plugin

We are using v2.3.8.0 of OJS, and we want to enable DOI plugin, but we don’t have the "Public Identifier Plugins"in the System plugins.

Thanks for the help.


Version 2.3.8 is extremely old. You should consider upgrading to use modern functionality.

Thank you. We know, but our informatic team tried and lost everything (we had a clone as backup).

Do you have another solution/suggestions other than upgrading? Many thanks