For disabled people in the UK: you may have come across locked disabled toilets requiring a Radar Key. The keys are £6.50, including delivery, & there is no gatekeeping. If you consider yourself disabled you can get one.
It's really made a difference to me at times, particularly when all toilets have been locked but I could at least use the Radar Key toilet.
You can buy them from Disability Rights UK
https://shop.disabilityrightsuk.org/products/radar-key