After some errors on the many pis I manage with raspbian buster, I had some no space left on device issues and saw that the /boot partition has only 54M /dev/mmcblk0p1 43M 23M 21M 53% /boot. I resized it after having moved and shrinked the / partition with gparted. On resizing the /boot partition gparted threw me an error but seemed to have done something anyways...
I now want to resize2fs /dev/mmcblk0p1 but it doesnt' work
sudo resize2fs /dev/mmcblk0p1
resize2fs 1.43.4 (31-Jan-2017)
resize2fs: Bad magic number in super-block while trying to open /dev/mmcblk0p1
Couldn't find valid filesystem superblock.