For arch use yay.
yay -S aur/anbox-git
Then choose the package and wait.
anbox session-manager
Error: [session_manager.cpp:146@operator()] Failed to start as either binder or ashmem kernel drivers are not loaded
sudo pacman -S linux-headers
Choose the respective version as per your kernel version.
At the end you will get output like this:
(1/3) Arming ConditionNeedsUpdate...
(2/3) Updating module dependencies...
(3/3) Install DKMS modules
==> dkms install --no-depmod -m anbox-binder -v 1 -k 5.4.85-1-MANJARO
==> dkms install --no-depmod -m anbox-ashmem -v 1 -k 5.4.85-1-MANJARO
==> depmod 5.4.85-1-MANJARO
sudo modprobe binder_linux
sudo modprobe ashmem_linux
systemctl enable anbox-container-manager.service
systemctl start anbox-container-manager.service