When Chromedriver is started in a pipeline via a gitlab-ci.yml file, further steps do not trigger

After installing up Chrome and Chromedriver via gitlab-ci.yml, Chromedriver is initiated by ‘- chromedriver --port=4444’. At this point, all steps stop as Chromedriver is running:

How do I ensure subsequent steps are initiated/completed in this scenario?

gitlab-ci.yml:

# Webapp automates testing
webapp:test:
  extends: .webapp:test
  stage: test
  allow_failure: true
  before_script:
	# Chrome and ChromeDriver dependencies
	- cd $APP_DIR
	- apt-get install -y wget unzip
	- wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add -
	- echo "deb http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list
	
	# Update the package list
	- apt-get update -y
	
	# Download and Install chrome
	- wget --no-verbose -O /tmp/chrome.deb https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb && apt install -y /tmp/chrome.deb && rm /tmp/chrome.deb
	
	# Download and install Chromedriver
	- mkdir /chromedriver
	- wget -q --continue -P /chromedriver "https://edgedl.me.gvt1.com/edgedl/chrome/chrome-for-testing/120.0.6099.109/linux64/chromedriver-linux64.zip"
	- unzip /chromedriver/chromedriver* -d /chromedriver 
	
	# Put Chromedriver into the PATH
	- chmod +x /chromedriver/chromedriver-linux64
	- export PATH="/chromedriver/chromedriver-linux64:$PATH"
	
	- |
	  if [ "$CI_COMMIT_REF_NAME" == "main" ]; then
		TEST_URL="https://rova.test.apps.goldcoast.qld.gov.au/"
	  elif [ "$CI_COMMIT_REF_NAME" == "test" ]; then
		TEST_URL="https://rova.test.apps.goldcoast.qld.gov.au/"
	  elif [ "$CI_COMMIT_REF_NAME" == "develop" ]; then
		TEST_URL="https://rova.dev.apps.goldcoast.qld.gov.au/"
	  fi
  only:
	changes:
	  - front-end/flutter-app/**/*
	  - docker/base/**/*
	  - back-end/serverless-functions/function-app/**/*
	  - back-end/serverless-functions/function-app.tests/**/*

flutterapp.gitlab-ci.yml

## Webapp test 
.webapp:test: &webapp_test
  image: $CI_REGISTRY_IMAGE/flutter:latest
  cache:
	paths:
	  - .npm/
	  - node_modules/
  script:
	- apt-get update && apt-get install -y jq
	- cd $APP_DIR
	- cd /chromedriver/chromedriver-linux64
	- chromedriver --version
	- chromedriver --port=4444
	- cd $APP_DIR
	- flutter drive --driver=test_driver/integration_test.dart --target=integration_test/start_page.dart -d web-server
  artifacts:
	paths:
	  - $APP_DIR/test-results/
  when: always
  allow_failure: true

Please note, I am relatively new to GitLab CI, as you can probably tell. I am aware there may be further issues to resolve to get the one test running, once I can get past this issue, but am happy to receive any feedback at all on the way I have put this together.