I am trying to install Endeavour os on a btrfs driive. I partitioned the drive using gparted before starting the installer but now when I select manual partition and select the one I want next is greyed out. Do I have to use the partitioned in the installer now?
I was able to do it manually before
So the only option that lets me continue the install is totally erasing the drive.
please be more detailed, what exactly you setup with gparted before starting installer, and waht exactly you choose inside installer partition screen?
So I went into gparted make 3 partitions one for bootloader and two / for Debian and Endeavour. Then set flags to bios grub for bootloader and /boot/efi for for Endeavour. Wrote that to disk.
Then in the installer the only option that doesn’t have next greyed out is erase disk.
So it’s dumb that Endeavour won’t let you make a blank partition. I deleted the unused partition and it worked.
we do use calamares and configure it to install EndeavourOS but we do not Develop the installer itself 
And there are some issues on the partition module at the moment inside calamares installer on installing Archbased systems. LVM also do not work as it should at the installer, and i have no idea about btrfs, Calamares have supported as a filesystem but i do not know if you cann install inside a preconfigured btrfs system.
what do you mean here?
Question: are you making the boot loader partition FAT32? You only mentioned btrf.
Yes boot is fat32.
I want to dual boot Debian and Endeavour. So I created two root file systems one for arch one for Debian. I left the Debian one just a blank btrfs partition but the installer didn’t like that apparently.
I usually don’t use btrf but i have quatro-booted distros in the past and several times left empty partitions to install later. With the Calamares installer. So I am not sure why it doesn’t work for you.
it can be good to just reboot after changing partitions with gparted in some cases