This link should take you to any stored keys.
https://account.microsoft.com/devices/recoverykey?refd=support.microsoft.com
The response there is You don’t have any BitLocker recovery keys uploaded to your Microsoft account.
Clicking on Not finding the key you need still? Learn more takes me to the page I was looking at yesterday with a bunch of useless suggestions, In your Microsoft account, On a printout you saved, On a USB flash drive, In an Azure Active Directory account, and Held by your system administrator.
The rest is Help with your Microsoft Account none of which look useful for recovering the key.
That is going away in Windows 11, although I believe it is still enabled.
But OP claims they didn’t back up the key, do it shouldn’t have been activated.
On newer devices that meet certain requirements, BitLocker (aka device encryption on Windows 10/11 Home devices) is enabled and the key is backed up automatically.
Apparently to a well hidden location.
Look for Dick Cheney to see if it is an undisclosed location.
I’d rather lose the data.
Good news: The tech was able to bring the CPU to life long enough to get the key and is in the process of getting the data off of the disk. Apparently it’s a slow process as it’s going to be overnight.
Not so good news: The replacement was DOA so back to CostCo for a swap. I haven’t unboxed it yet. According to the label it’s Win 11-S which, from what I’ve found out means it can load only software from the MS store and Edge is the default browser. Fuck that.
The worse news: The car is in the shop for making a weird noise. This has not been my weekend.
Brilliant. 
Seriously, in the grand scheme of things, you are well ahead. People underestimate the pain of data loss until it hits them. Most things can be fixed or replaced. Data can’t.
Good news that they could get your data. Backup, backup, backup!
S mode can be turned off in a few clicks at no cost. https://support.microsoft.com/en-us/windows/switching-out-of-s-mode-in-windows-4f56d9be-99ec-6983-119f-031bfb28a307
Yeah, with the stern warning you can’t ever turn it back on again.
Gosh
So, I’ve set up the new laptop. At no time did it tell me that the drive was encrypted – I had to look for it in Settings. There was no popup suggestion to back up the key, just a link in tiny type way down at the bottom of the page. You betcha I did and I will be checking the two desktops as well.