Man pages matching name mkfs.exfat in section 8:

mkfs.exfat.8.en	debian 10 / exfat-utils
mkfs.exfat.8.en	debian 11 / exfat-utils
mkfs.exfat.8.en	debian 11 / exfatprogs
mkfs.exfat.8.en	debian 12 / exfatprogs