Error with running Ruby `initialize’: wrong number of arguments (given x, expected x) (ArgumentError)

Error with Ruby

I was following an instruction to run a sample GitHub App based on Ruby with a bundle and encountered a following error:

/usr/local/lib/ruby/gems/3.0.0/bin/gems/mustermann-1.0.3/lib/mustermann/regular.rb:22:in`initialize’: wrong number of arguments (given 2, expected 1) (ArgumentError)