Advice on Fit Note request, please

I sent them a message to ask why I am being asked for a fit note when it says that I am not required to look for work or do work related activities.
And the message I got back from Northern Ireland is they were sending my message to my local Job Centre.

I know it's not what you suggested but no one at their end has mentioned anything about a "Health Journey" and i wanted to know the reason why they are asking.

I have started the ball rolling concerning getting evidence of my medical conditions just in case.

Hi again David
You've been really helpful.
I asked in my journal why they were asking for a fit note, when it says in the " Work Plan" section of my UC page that I'm not required to look for work, and said that I am a carer for my son.
And they just replied that they were passing on my question to my jobcentre, so I'm just waiting for an answer from the jobcentre.
It might sound stupid, but I just want to hear them say I don't need to get a Fit note.
The only reason I can think is that I need to prove that I'm eligible to get the PIP payments that I do get.
It seems that they want some kind of answer from me about this.

Hi David
I've just had a long chat with someone at the jobcentre, the lady who looks after my son's case actually.
She advised that it would be best for me to go down getting a fit note, because she said if I do what you suggested and say I don't want to go on the health journey then chances are that I'll get called in and they'll expect me to start looking for employment, which physically I just can't handle at the moment due to my conditions.
She reckons that with my medical issues that they probably won't take it any further.
I don't really know what to do next, but I'm going to see if I can get a fit note just in case.

Have a great weekend
Paul