Hello and welcome Teddy24. In a word, well phrase, not a lot, and I'm sorry to sound so negative your situation.
As long as someone has capacity there isn't a lot you can do as far as I know (UK England rules), so involvement from social services may help, vulnerable adult at risk possibly.
Plenty of key phrases, at risk of incorrect medication, poor hygiene, danger to themselves or others, not eating...any number of things can trigger a social services assessment, have a read around on here
Bottom line is that if a person has capacity and no issues of concern to social services (after they have done an assesment) then if they choose to go into care their assets, money, property could well end up paying for the care more likely than not, well pretty likely from what you say.
Let's say about 800 to 1,000 pounds per week in a care/nursing home as a rough figure for the care home or nursing home costs, as long as they have assets the state doesn't pay except for certain exempt circumstances.
I doubt you can get a parent into care without a Deprivation of Liberty Safeguarding Order (dols) or being sectioned under the mental health act.
Sorry if that doesn't sound too helpful but it's the state who puts people places against their wishes, families place people there.
Get social services on side, medical healthcare professionals or whoever but without agreement it's not something you can make happen or that many homes would agree to do without the legal framework.
Sorry I've read back and o sound pretty harsh but it is what it is and as you have been told nothing you can do to make someone with capacity go into care. K