NI credit help on benefits

I have my migration notice from Income ESA to UC and the deadline is soon, but I am not sure that I want to put myself through the stress of it all. I am already on PIP and live with my family so my bills are minimal. I am currrently in the support group of ESA. My only worry is that I will no longer automatically get National insurance credits for state pension and I have approx 5 years more to go to get a full pension. I haven't been able to work for quite a few years, so as far as I know I can't claim New style ESA. I don't have any children, partner etc.. So I am wanting to know is there any way to not claim UC for the money, but just be able to get the NI credits someway? or would I just have to buy them myself? any help appreciated.

Thanks I didn't realise you could still apply for it. Do you know if you have to explain why you don't want to be on UC? and is the application form for new style ESA credits mean that I will have to start from the beginning with sick notes etc..? as I am in the support group of income based ESA at the minute, but if I don't migrate to UC, do I have to start all over again and get reassesed which group to be in (working or none working)?