Filed tax return already how to file Capital gain tax

I filed my 21/22 Self assessment and realised I need to file a capital gains tax report, I tried creating a Capital gain tax account but it wouldn't allow me. I tried looking for the paper forms but they only available is 22/23 and 23/24. It mentioned any earlier is to call up asking for the form, I tried calling all week and each time I am in the automated of the call it just hangs up on me, whether it was morning, noon or late noon. I am not sure what to do? How can I file my capital gains tax if I cannot get a form? I understand it is late but I want to get it sorted as soon as possible before more penalty is added on. I was wondering if anyone can help me.

Hi,

A SA108 (2022) can be downloaded here:

Self Assessment: Capital gains summary (SA108)

As you have already submitted your tax return for 2021 to 2022, please send the completed capital gains form, together with a calculation of your gain, to:

HM Revenue and Customs
Self Assessment
BX9 1AS.  

Please ensure that your UTR number is on the form.

Thank you.