How can I get passphrase to unlock my drives when I am in a OS other than windows (dual-boot system of Linux+Windows) ?

I bought my laptop 4 months back and don't remember having any 'passphrase'. I am sure that I was not provided anything when I bought it. I have pre-installed windows 11(Home). I installed Ubuntu 22.04 LTS version (as I need to learn Linux for my university) along with my windows as a dual boot system. So I have all the previous data stored in my disks/drives(Let's assume these are E:), as I manually created disk partitions for Linux.

When I am using windows I can access all data from drive "E:"; But when I am in Linux and try to open my drive it says something like "a passphrase is needed to access encrypted data on.........". In Linux, I am only able to access the /home directory that I made during installation. But I want to access the E: drive too. Is there any way ??

I understand that windows don't support ext4 which is why '/home' directory is not even visible in Windows. But the NTFS drives (drive E: and other drives) should be accessible from both OSs.

Note: When I open Disc Management System (in windows), it shows my E: driver is 'BitLocker Encrypted'. I ran PowerShell (run as administrator) and tried the command(as suggested by an article) :

manage-bde -protectors -get E:

But PowerShell returns:

Volume E: [New Volume]

All Key Protectors

ERROR: No key protectors found.

As I am not an expert, I would be very glad to have detailed instructions on how to find the passphrase or at least whom/which organization to contact to get passphrases.

Laptop: HP 14s