I ran into the same issue. Unfortunately I didn't get any clue from the documentation. There's this stackoverflow answer which gave me a hint on how to go about it.

I soloved this by adding interper property to my ecosystem.config file.

        script: './src/server.ts',
        interpreter: 'node',
        interpreter_args: "--experimental-transform-types --max_old_space_size=1400 --env-file=./.env.development",