grub2 stands for GRand Unified Bootloader 2.
Run grub2-mkconfig on Fedora Workstation 30 to detect new installation of Microsoft Windows 10 and update /etc/grub2.cfg file.
[tuyen@g73jh ~]$ grub2-mkconfig -o /etc/grub2.cfg grub2-mkconfig: You must run this as root [tuyen@g73jh ~]$ sudo !! sudo grub2-mkconfig -o /etc/grub2.cfg Generating grub configuration file ... Found Windows Recovery Environment on /dev/sda1 Found Windows 10 on /dev/sda2 done [tuyen@g73jh ~]$