Using escpos Ruby gem with rails application gives out error

Question

I'm trying to run following library inside a rails application and when I try to run their sample code inside my controller, I'm getting the following error.

My sample code is as following,

      @printer = Escpos::Printer.new
      @printer << "Some text"
      @printer << Escpos::Helpers.bold "help"
      @printer.cut!

This is the library I'm trying to use.

https://github.com/escpos/escpos

Answer 1

Can you try this?

@printer << Escpos::Helpers.bold('help')

Should work!