print_buttons preference not defined (NoMethodError)

[1990prashant]

Following readme of master and I get

/gems/ruby-2.3.1/gems/spree_core-3.1.0/app/models/spree/preferences/preferable.rb:62:in `has_preference!': print_buttons preference not defined (NoMethodError)

This is how my config looks like

Spree::PrintInvoice::Config.set(print_buttons: 'invoice')

[rogodani]

Hi,

I have the same problem with spree 3.7.3 do you have any solution for this?

Thank you