"Perhaps looking at the upcoming change in 24H2 as well as the boot bug, Microsoft has now added a bunch of new guides to its official website regarding BitLocker device encryption. In particular, two of them are certainly the most useful ones which walk users through finding their BitLocker recovery key and backing up the said key." - Sayan Sen, Neowin
The Neowin article describes two ways to access the Bitlocker key: via your MS account and via work/school account. I recommend taking a peek at the article.
MS has detailed the steps to create a Bitlocker key backup, and that's in the article as well.
A good explanation of Bitlocker as well as a local vid and a YouTube vid are provided here: https://support.microsoft.com/en-us/windows/bitlocker-overview-44c0c61c-989d-4a69-8822-b95cd49b1bbf
Also, on the left margin there are links to additional guides.
1) Finding your recover key: https://support.microsoft.com/en-us/windows/find-your-bitlocker-recovery-key-6b71ad27-0b89-ea08-f143-056f5ab347d6
2)Backup your Bitlocker recovery key: https://support.microsoft.com/en-us/windows/back-up-your-bitlocker-recovery-key-e63607b4-77fb-4ad3-8022-d6dc428fbd0d