It should use basic auth and an http post to generate a payload that matches the following:
%Plug.Conn{adapter: {Plug.Adapters.Cowboy.Conn, :...}, assigns: %{},
before_send: [#Function<1.54385806/1 in Plug.Logger.call/2>,
#Function<0.18961230/1 in Phoenix.LiveReloader.before_send_inject_reloader/1>],
body_params: %{"esme" => "lwr_orange_burkina_faso",
"inbox_uuid" => "4833976e-84bf-43b9-83f9-ae8e4608511c",
"message_uuid" => "007", "recipient" => "alexis", "sender" => "taylor",
"text" => "hi mom!"}, cookies: %Plug.Conn.Unfetched{aspect: :cookies},
halted: false, host: "localhost", method: "POST", owner: #PID<0.496.0>,
params: %{"esme" => "lwr_orange_burkina_faso",
"inbox_uuid" => "4833976e-84bf-43b9-83f9-ae8e4608511c",
"message_uuid" => "007",
"openfn__inbox_uuid" => "4833976e-84bf-43b9-83f9-ae8e4608511c",
"recipient" => "alexis", "sender" => "taylor", "text" => "hi mom!"},
path_info: ["smpp", "4833976e-84bf-43b9-83f9-ae8e4608511c", "send"],
path_params: %{}, peer: {{127, 0, 0, 1}, 45132}, port: 4000,
private: %{OpenFn.Router => {[], %{}}, :phoenix_action => :send,
:phoenix_controller => OpenFn.SMPPController,
:phoenix_endpoint => OpenFn.Endpoint,
:phoenix_layout => {OpenFn.LayoutView, :app}, :phoenix_pipelines => [],
:phoenix_route => #Function<67.39742813/1 in OpenFn.Router.match_route/4>,
:phoenix_router => OpenFn.Router, :phoenix_view => OpenFn.SMPPView,
:plug_session_fetch => #Function<1.131660147/1 in Plug.Session.fetch_session/1>},
query_params: %{}, query_string: "", remote_ip: {127, 0, 0, 1},
req_cookies: %Plug.Conn.Unfetched{aspect: :cookies},
req_headers: [{"host", "localhost:4000"}, {"connection", "keep-alive"},
{"content-length", "178"},
{"user-agent",
"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.90 Safari/537.36"},
{"cache-control", "no-cache"},
{"origin", "chrome-extension://fhbjgbiflinjbdggehcddcbncdddomop"},
{"content-type", "application/json"},
{"authorization", "Basic YWRtaW46YWJjMTIz"},
{"postman-token", "7be1c79d-f3ac-4095-0b8e-db02649dd2a7"}, {"accept", "*/*"},
{"accept-encoding", "gzip, deflate, br"},
{"accept-language", "en-US,en;q=0.8,es;q=0.6"}],
request_path: "/smpp/4833976e-84bf-43b9-83f9-ae8e4608511c/send",
resp_body: nil, resp_cookies: %{},
resp_headers: [{"access-control-allow-origin", "*"},
{"access-control-expose-headers", []},
{"access-control-allow-credentials", "true"}], scheme: :http, script_name: [],
secret_key_base: "J+Z7Ny9pWvr0hoKY3vzgL7LLpg6tarNxWB9FcWeaKJiYzsUvlBBMBQS90j9sBgnA",
state: :unset, status: nil}