NI for a foreign based employer

Hello. I am permanent employer since 9/2023 of a Polish based company with no PAYE set up in the UK, I am resident in the UK and have an HMRC Certificate of Residence regarding doubletaxation betwen the UK and Poland and do not pay tax in Poland. For income I think it's all clear and I submitted self-assessment for 2023/24. For the National Insurance I was advised to fill form CF83 by the tax accountant - can you confirm this is the right approach? Or what number can I call to get clarifications? Regards, 

Name removed admin 

Hi Andrea,
You can ring the employers helpline for advice regarding whether a direct payment scheme could be set up for the payment of National Insurance contributions.
If not, the CF83 would be the correct form to complete if you want to pay National Insurance contributions on a voluntary basis.
The contact number for the employers helpline is 0300 200 3200, lines are open from 8am to 6pm, Monday to Friday.
Employers: general enquiries
Thank you.