Self Assessment Tax Return

I am an oversea landlord and it's my first time to submit self-assessment tax return. As I do not have any National Insurance number, I can't do the tax return online. I had written to HMRC for advice of registration in early May 2023 but no updates so far. Should I consider submitting paper form? if so, may I clarify: 1. I need to call HMRC directly to obtain the SA100 ; 2. then complete SA 100 and SA105; 3. post the paper forms to HMRC Am I correct? or did I miss anything? For advice please.

Hi
As a non resident, you cannot file online anyway using HMRC software as you need to complete the residence section that is not available.
A paper form is therefore required unless you wish to purchase 3rd party software.
Your return will therefore be SA100,SA105 AND SA109.