The terminology is a bit of a minefield, isn't it?
'Disabled toilets' were designed for, and intended for, people with disabilities who physically need extra adaptations to be able to use the toilet, and sufficient space to enter and exit the space in a wheelchair, and transfer to the toilet from the side.
So they are 'accessible' meaning wheelchair accessible, specifically, or 'adapted' toilets, which are for the use of people with disabilities who need the extra space, supports, and location at the appropriate height of the facilities.
But they quickly became known as 'Disabled Toilets' - as LesserCelandine points out, they are not 'disabled', they work perfectly well
, so technically they should be called 'adapted' or 'accessible' but that ship has sailed: the are known as 'Disabled Toilets'.
I won't go into the issue of who should use 'the disabled toilet', it's such a difficult area, e.g. invisible disabilities, mental health issues etc.
We don't 'police bathrooms', we can't do checks on who is using the women's toilet or the disabled toilet or the men's toilet, it works on trust, so whether or not a person needs to use the 'disabled' toilet is a decision for the individual to make. We just have to trust that people are being respectful in making that decision. That's all we can do.