using e2fsck and un mounting

[Bill Cunningham]

     How do you mount fedora 36 so you can use e2fsck? I seem to have a 
lot of filesystem problems, but no way to mount even with the network 
installation USB. Booting creates errors in the system services. I was 
mounted ro and was able to use

umount -o,remount,rw /dev/sda3 /

and remounted rw to save the root under '/' and not 'none' in fstab.

How do you set the filesystem to run e2fsck at reboot? That would be 
excellent. Everything I have tried doesn't work.