Piston worker with singularity

Hi I have changed the launch script for piston worker to sth like below, after pulling the docker image and convert to .sif.

`singularity exec --bind /data/user_data/yeemanc/piston/packages:/piston/packages --env PORT=2000 --env PISTON_COMPILE_TIMEOUT=60000 --env PISTON_RUN_TIMEOUT=60000 --env PISTON_OUTPUT_MAX_SIZE=1000000000 --env PISTON_MAX_FILE_SIZE=1000000000 --env PISTON_DISABLE_NETWORKING=true --env PISTON_REPO_URL=https://github.com/guipenedo/piston/releases/download/pkgs/index piston.sif bash -c "sed -i '/app.use(body_parser.urlencoded/c\ app.use(body_parser.urlencoded({ extended: true, limit: \\\"512mb\\\" }));' src/index.js && \
sed -i '/app.use(body_parser.json/c\ app.use(body_parser.json({ limit: \\\"512mb\\\" }));' src/index.js && \
node src"`

However, I am getting the error `sed: can't read src/index.js: No such file or directory`. Would anyone happen to have any insights on how to fix this? Any help is appreciated! Thanks!