Question regarding hosting server and client in different projects

I need to host Hangfire server in different assembly from the client. I did a demo and all works well. My only problem is: I have a shared library that contains methods that are invoked when job is queued. This works fine when both client and server project under same solution. In real live: they are not. Server is hosted in .Net Core Web API project, where is client is a classic ASP.Net project. Problem: how do share a library that contains methods that are being invoked? I was thinking a private NuGet repo. But it’s an overkill setting a local NuGet repo just for one library. Any ideas are greatly appreciated.