Am I writing a shell script correctly to start 2 processes in a Docker container?

Question

bash

Previously, I didn’t have to write a shell script and use ENTRYPOINT in docker ... In practice, checking for correctness by sorting through errors is currently not the best option for me, since build takes a long time (about an hour).
I want to be sure right away that the least Dockerfile and script.sh are written correctly ...

Dockerfile

FROM ubuntu:18.04
...
COPY script.sh ./script.sh
ENTRYPOINT ./script.sh

script.sh

#!/bin/bash
python3 daemon_clean_wav.py start
gunicorn --access-logfile - -w 4 --bind 0.0.0.0:5000 controller:app --timeout 15000