Incapable of work, what is my class of NIC?

I am incapable of work because of illness. May I apply for class 2 NIC? How can I report my health condition to HMRC? Thank you so much for offering a great help to me!

Hi wyllis Cheung,
If you are not receiving a benefit which has a credit awarded to maintain your National Insurance account for State Pension purposes, then you may pay voluntary Class 3 National Insurance contributions.
This would be for  State Pension purposes only.
If you have access to your Personal Tax Account then you may wish to check this shortly after the tax year to see if a payment of voluntary class 3 contributions is required.
Thank you.