try this:
apt install libffi7
create launch script:
#!/bin/bash
_pwd=dirname $(readlink -e "$0")
LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libffi.so.7 $_pwd/Defold
and launch it .
or launch it using:
LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libffi.so.7 ./Defold
(solution by @sashikknox )