How do I create new user from scratch - ruby-on-rails

Question

I'm still working on my very first Ruby on Rails project. The latest issue I'm dealing with is the user management system. I tried using Devise but I couldn't get past a certain error so I decided to create my sign in/login system manually. I'm using Ruby 3.0.2 w/ Rails 7.0.0alpha2.
I got a lot farther this manual way but I'm getting 'undefined method `cost' for BCrypt::Engine:Class' I've googled and they mention changing the version of bcrypt, I did with no luck
They mention going to my user_controller and changing my create method from old code to this '#user = User.new(user_params)' doing this changed my error from 'forbidden' to the error I'm currently writing to you about.
Not to sure on where my issue is, my guess is somewhere in the model or controller, thank your for your time!
User Controller
class UsersController < ApplicationController
def new
#user = User.new
end
def create
#user = User.new(user_params)
if #user.save
session[:user_id] = #user.id
redirect_to root_url, notice: "Thank your for signing up!"
else
flash[:danger] = 'Invalid email/password combination'
render "new"
end
end
private
def user_params
params.require(:user).permit(:email, :password, :password_confirmation)
end
end
Session Controller
class SessionsController < ApplicationController
def create
#user = User.find_by_email(params[:email])
if #user && #user.authenticate(params[:password])
session[:user_id] = user.id
redirect_to root_url, notice: "logged in!"
else
flash.now.alert = "Email or passwrod is invalid"
render "new"
end
end
def destroy
session.delete(:user_id)
#current_user = nil
end
end
User Model
require 'bcrypt'
class User < ApplicationRecord
include BCrypt
validates :email, uniqueness: true
has_secure_password
def user_params
params.require(:user).permit(:email, :password, :password_confirmation)
end
end
Routes
Rails.application.routes.draw do
get 'sessions/new'
resources :users, only: [:new, :create]
resources :fighters
resources :sessions
get 'home/about'
root 'home#index'
get 'signup', to: 'users#new', as: 'signup'
get 'login', to: 'sessions#new', as: 'login'
get 'logout', to: 'sessions#destroy', as: 'logout'
end
Error
User Controller
User Model
Routes
Session Controller

Answer 1

I logged on this morning and all of a sudden my problem was fixed! Maybe something having to do with the terminal closing because I compared the code I posted here and what I have in my files, very little changes.
1 change I made was adding # to 'session[:user_id] = user.id' to make '#user.id'
After I was able to log on, I was getting an error to log off. The change I made was adding 'session.clear' and 'redirect_to login_path' in my destroy method.
Both changes made in my sessions_controller.rb
I also added "delete 'sessions', to: 'session#destroy'" to routes.rb