mycelium_gear_api.rb

require "net/http"

# You can get the api_gateway_id value from your gateway's info 
# in the dashboard panel.
gateway_id = 17171

# It determines the amount to be paid for this order.
amount_in_btc = 2.5

# When a callback request is issued, this callback_data param will
# be returned back.
callback_data = "Order number 47"
 
# It generates payment request URL 
url = "https://api.gear.mycelium.com/gateways/#{gateway_id}/orders"
url << "?amount=#{amount_in_btc}"
url << "&callback_data=#{callback_data}"

uri = URI(url) 

# Does payment request to Mycelium Gear developer API
Net::HTTP.start(uri.host, uri.port, use_ssl: true) do |http|
  req = Net::HTTP::Post.new(uri)
  http.request(req)
end