So truck drivers don't overnight at UK supermarkets? What do they do when they can't park at a truck stop and they're out of legal driving hours for the day? I

So truck drivers don't overnight at UK supermarkets? What do they do when they can't park at a truck stop and they're out of legal driving hours for the day? I'm driving a semi truck. I'm parked in a Kroger parking lot in Fort Worth TX (in an out of the way corner), having slept here overnight. Kroger is unusual, I mostly use Walmart when I can't find "legitimate" parking, because the lots are generally bigger, near interstates, and easier to navigate a truck and 53 foot trailer through. I tried a nearby truck stop first, but there were no spaces. Two nights before I slept on an interstate on ramp on Alabama. There were ten to fifteen other trucks on that same ramp, and when I left the next morning most of the subsequent ramps were full of trucks. Which is to say, I'm a frequent Walmart parker, by necessity. I've never seen a specific time limit at a Walmart lot. Sometimes I see no truck parking signs at Walmart, or no overnight signs (and sometimes i park there anyway, especially if there are other trucks there). I have seen time limit signs at some rest areas, for six or eight hours. Yet truckers are required to stop for at least ten hours between working days. I ignore those signs. And by the way, depending on the part of the country, those rest area off and on ramps are usually also packed with trucks. I've only been told to move once, waking me from sleep, when I accidentally parked in a paid reserved space at a truck stop. (Yep, they have those, more and more.)