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

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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?