MEGAsync with the crash handler removed, allows building MEGAsync on aarch64 and other non-supported architectures.
I am not affiliated with Mega.
Install flatpak, flatpak-builder, and use flatpak to install org.kde.Sdk.
flatpak-builder --user --install --force-clean build nz.mega.MEGAsync.yml
The app will run insude the flatpak sandbox and won't have filesystem access. Use flatpak override... or flatseal to give it access to the directory where you want to store the synced files.