Insert into foreign key rails

How can I insert into the table of reminders having a foreign key with the user table please help me newbie here, i tried to looking for answers but sadly I doesn't work

Admin Home/Index

<h2>Add a Reminder</h2>
<%= form_for :reminder, url: admin_reminders_path do |f| %>
<p>
    <%= f.label :reminder %><br>
    <%= f.text_area :reminder %>
</p>
<p>
    <%= f.label :date %>
    <%= f.date_field :date %>
</p>
<p>
    <%= f.submit %>
</p>
<% end %>


------------------------------------------------------------------------

Controller

class Admin::RemindersController < Admin::BaseController
def new
end

def create
    #render plain: params[:reminder].inspect
    @reminder = Reminder.new(reminder_params)
    @reminder.save
    redirect_to admin_root_path
end

private 
def reminder_params
    params.require(:reminder).permit(:reminder,:date)
end
end
----------------------------------------------------------------------------

Reminder Model

class Reminder < ApplicationRecord
belongs_to :user
end
---------------------------------------------------------------------------

User Model

class User < ApplicationRecord
 has_many :reminders
end 

----------------------------------------------------------------------------
 This is the database
 id         | bigint(20) | NO   | PRI | NULL    | auto_increment |
| reminder   | text       | YES  |     | NULL    |                |
| date       | date       | YES  |     | NULL    |                |
| user_id    | bigint(20) | YES  | MUL | NULL    |                |
| created_at | datetime   | NO   |     | NULL    |                |
| updated_at | datetime   | NO   |     | NULL    |                
----------------------------------------------------------------------------

Routes

Rails.application.routes.draw do
resources :users

get 'login', to: 'login#index'
get 'logout', to: 'login#logout'
post 'users/login', to: 'users#login'

namespace 'admin' do
    get 'home', to: 'home#index'
    resources :employees
    resources :reminders
    #payroll
    get 'payroll/summary', to: 'payrolls#summary'
    root 'home#index'
end

namespace 'employee' do
    get 'home', to: 'employee/home#index'
    root 'employee/home#index'
end

namespace 'bookkeeper' do
    get 'home', to: 'home#index'
    root 'home#index'
end

root :to => "login#index"
get "*path" => redirect("/")
# For details on the DSL available within this file, see 
http://guides.rubyonrails.org/routing.html
end

I want to insert the reminder, date and the user who inserted the reminder. Thanks for helping me.