Use

Add this as a part to your snapcraft.yaml:

parts:
    snapcraft-preload:
        source: https://github.com/sergiusens/snapcraft-preload.git
        plugin: cmake
        cmake-parameters:
          - -DCMAKE_INSTALL_PREFIX=/
        build-packages:
          - on amd64:
            - gcc-multilib
            - g++-multilib

And precede your apps entry like this:

apps:
    app-name:
        command: bin/snapcraft-preload $SNAP/<binary>

If you're using the desktop-launch launcher from the ubuntu/snapcraft-desktop-helpers, place snapcraft-preload after desktop-launch in the app command.