Get the token using the API of Qiita

get_token.rb

require 'net/https'

Net::HTTP.version_1_2

http = Net::HTTP.new('www.qiita.com', 443)

http.use_ssl = true
http.verify_mode = OpenSSL::SSL::VERIFY_NONE

#twittername or githubname@github
url_name = UserName

#Qiita's password
passwd = Password

response = http.post( "/api/v1/auth", "url_name=#{url_name}&password=#{passwd}" )

puts response.body

Using Faraday Ruby gem is better.
https://github.com/technoweenie/faraday