Ruby: add_reference in migration throws error: Table has no foreign key for

I have this migration:

class AddNotificationSettingToHistoricals < ActiveRecord::Migration[6.1]  def change    unless foreign_key_exists?(:sms_historicals, column: :notification_setting_id)      add_reference :sms_historicals, :notification_setting, foreign_key: true    end    unless foreign_key_exists?(:email_historicals, column: :notification_setting_id)      add_reference :email_historicals, :notification_setting, foreign_key: true    end  endend

but when I run it, it throws this error:

Table 'email_historicals' has no foreign key for notification_settings

What I don't understand is that I have these in the migration:

unless foreign_key_exists?(:email_historicals, column: :notification_setting_id)

Which does throw false.. so yes there is no foreign key, that's why I'm trying to add it.. Yea I'm not sure why its doing this.. Any ideas?