If you have a job you like at all, I really wouldn't give it up if I were you. If you're working but providing at least 35 hours of care per week you can still claim Carer's Allowance; and in any case that allowance is nothing like an income.
This is a good question for Country Mouse to answer if this person lives in the UK. Its almost 11:30am EST so its 4:30 PM in the UK. So CM may not be home yet.
If you have a job you like at all, I really wouldn't give it up if I were you. If you're working but providing at least 35 hours of care per week you can still claim Carer's Allowance; and in any case that allowance is nothing like an income.
But if you must, try this section: https://www.gov.uk/carers-credit
It's about "filling gaps" (in your tax history), as they put it.
https://www.litrg.org.uk/tax-guides/disabled-people-and-carers/caring-someone/pension-and-national-insurance-carers#:~:text=The%20main%20benefit%20available%20to,a%20qualifying%20year%20that%20year.