422 Error: (Unprocessable Entity) - ruby-on-rails

Question

I am new, so I apologize in advance if there is some issues with my explanation of my issue, I am using Ionic v1. on the frontend and this ruby tutorial for the backend: https://www.simplify.ba/articles/2016/06/18/creating-rails5-api-only-application-following-jsonapi-specification/.
I am trying to create a user and have that information stored in the backend, but continue to run into a 422 (Unprocessable Entity Error). I have read many different forums, but am stuck.
Here's my front end:
.controller('SignupCtrl', function($scope,SignupSession,$ionicPopup) {
$scope.signup = function(full_name, password, repeat_password) {
var user_session = new SignupSession({ user: { full_name: full_name, password: password }});
user_session.$save(
function(data){
window.localStorage['full_name'] = full_name;
window.localStorage['password'] = password;
$location.path('/app/playlists');
},
function(err){
$ionicPopup.alert({
title: 'An error occured',
template: err["data"]["error"]
});
}
);
}
})
.factory('SignupSession', function($resource) {
return $resource(window.server_url + "/users.json") //application/vnd.api+json
})
Here's my backend:
User Controller:
def create
user = User.new(user_params)
if user.save
render json: user, status: :created, meta: default_meta
else
render_error(user, :unprocessable_entity)
end
end
def user_params
ActiveModelSerializers::Deserialization.jsonapi_parse(params)
end
Sessions Controller:
def create
data = ActiveModelSerializers::Deserialization.jsonapi_parse(params)
Rails.logger.error params.to_yaml
user = User.where(full_name: data[:full_name]).first
head 406 and return unless user
if user.authenticate(data[:password])
user.regenerate_token
render json: user, status: :created, meta: default_meta,
serializer: ActiveModel::Serializer::SessionSerializer and return
end
Here's my log and info from Google Chrome:
Started POST "/users.json" for 127.0.0.1 at 2017-08-04 12:40:39 -0700
Processing by UsersController#create as JSON
Parameters: {"user"=>{"full_name"=>"btejes#yahoo.com", "password"=>"[FILTERED]"}}
[1m[35m (0.1ms)[0m [1m[36mbegin transaction[0m
[1m[35m (0.1ms)[0m [1m[31mrollback transaction[0m
[active_model_serializers] Rendered ActiveModel::Serializer::ErrorSerializer with ActiveModelSerializers::Adapter::JsonApi (0.29ms)
Completed 422 Unprocessable Entity in 6ms (Views: 0.7ms | ActiveRecord: 0.2ms)
{errors: [{source: {pointer: "/data/attributes/password"}, detail: "can't be blank"},…]}
errors
:
[{source: {pointer: "/data/attributes/password"}, detail: "can't be blank"},…]
Does it have something to do with the content type needing to have, "application/vnd.api+json" in the front end? Any help would be greatly appreciated, and I apologize in advance that this post is on the longer side.
Ben