Распечатала все документы, зашла в личный кабинет посмотреть адрес куда посылать письмо, а там надпись
Tax Forms
If you'd like to claim the benefits of the income tax convention, please download and fill out the required forms and send them to the specified email address
Our mailing address is:
income-tax@pixta.co.jp
*Please write "APPLICATION FORM FOR INCOME TAX CONVENTION" in the title of the email.
*Please write your User No. and name in the email.
*Please send the forms as a PDF file
Once the forms have been reviewed and accepted, the notification will appear on this page and the new tax rate will be applied to your unpaid earnings.
отправила им на мыло, буду ждать пока появится обновление в личном кабинете