application_controller.rb

class ApplicationController < ActionController::Base
  # this addition might/might not be needed. Try it without first.
  before_action :configure_permitted_parameters, if: :devise_controller?

  def configure_permitted_parameters
    devise_parameter_sanitizer.for(:account_update) { |u| 
      u.permit(:password, :password_confirmation, :current_password) 
    }
  end
end

view.html.erb

<%= link_to "Change your password", edit_user_registration_path %>