Packaged blueprint project doesn't load a custom plugin

Hi, I don’t seem to have access to my custom plugin in a packaged blueprint project.
It is all fine in editor, but when starting the packaged game the plugin refuses to load. I tried the simplest plugin, just with one blueprint printing hello and still nothing. The log from game says:

[2019.01.14-22.35.04:289][ 0]LogPackageName: Error: DoesPackageExist: DoesPackageExist FAILED: ‘/bluePlugin/NewBlueprint’ is not a standard unreal filename or a long path name. Reason: Path does not start with a valid root. Path must begin with: ‘/Engine/’, ‘/Game/’, ‘/Paper2D/’, ‘/CryptoKeys/’, ‘/MeshEditor/’, ‘/DatasmithContent/’, ‘/VariantManagerContent/’, ‘/MediaCompositing/’, ‘/OculusVR/’, ‘/SteamVR/’, ‘/Config/’, ‘/Script/’, ‘/Memory/’, or ‘/Temp/’
[2019.01.14-22.35.04:289][ 0]LogStreaming: Error: Couldn’t find file for package /bluePlugin/NewBlueprint requested by async loading code. NameToLoad: /bluePlugin/NewBlueprint

I have the plugin under Plugins in my project path. Is there a place I should declare the path to it again?
Is it even possible to package a custom plugin in blueprint project?
Just to mention I package easily in a c++ based project, but it is not optimal when working with a ready made blueprint one.