Syntax error during migration. How to fix?

Question

PostgreSQL

Forgot to add the date of birth field to the registration form
Created a new migration

class AddBirthdayColumnToUsers < ActiveRecord::Migration[6.0]
  def change
    add_column table_name :users, column_name :birthday, type :string
  end
end

I write in the console rake db:migrate
I get an error:
syntax error, unexpected symbol literal, expecting `do' or '{' or '('

So far I could not figure it out myself, so I decided to ask here

Answer 1

I wrote like this and it all worked, but why it didn’t work before and why there was such an error still didn’t understand

class AddBirthdayColumnToUsers < ActiveRecord::Migration[6.0]
  def change
    add_column  :users, :birthday, :date
  end
end