Update 2: Finally did it by following the first option I explained in my own comment (i.e. backup and reinstall)

Update 1: I also updated the UEFI just to be sure and the issue persists as expected

Sorry if the post is long, trying to give each relevant detail.

My system has two drives, the first for Linux and the second for Windows.
Initially I had OpenSUSE MicroOS on the first and I could boot into Windows through the UEFI, but then I installed Fedora on it and lost the ability to get into Windows since. I thought that it had a boot partition on its own drive, but I guess I was wrong since now that I checked the partitions, there is no FAT32 partition on there.

(in text form)

nvme0n1                                       931,5G disk              
├─nvme0n1p1                                      16M part              
├─nvme0n1p2                                   930,8G part  BitLocker   
│ └─bitlk-66306                               930,8G crypt ntfs
└─nvme0n1p3                                     692M part  ntfs

Unlike on my Linux drive

(in text form)

nvme1n1                                       931,5G disk              
├─nvme1n1p1                                     600M part  vfat        /boot/efi
├─nvme1n1p2                                       1G part  ext4        /boot
└─nvme1n1p3                                   929,9G part  crypto_LUKS 
  └─luks-353e522f-c0f3-4167-99fc-90d576a734e8 929,9G crypt btrfs       /var/home

So I probably destroyed the content of the boot files in its installation process.

I'm able to access my BitLocker encrypted drive through Fedora, so if I have to reinstall I can still make a backup (it wasn't very important to me either way).
I also fired up a Windows recovery drive to see if it detected the system and it does, I haven't yet looked at what the recovery drive can do, so if that's the key to solving this let me know.

The actual question

So at this point I wonder: is there a way to restore the Windows boot option? Would I have to do it in some GRUB config or do I have to/can I create a boot partition on the Windows drive too and somehow write the bootloader there?