gitlab runner not loading the correct node version

I have installed gitlab runner in my server and binded with the gitlab repo and pipelines.

here's my gitlab-ci.yml

image:
  name: node:14.9.0
stages:
  - install
  - deploy

install for production:
  image: node:14.9.0
  stage: install
  tags:
    - mytag
  only:
    - master
  script:
    - node -v
    - /home/gitlab-runner/.nvm/versions/node/v14.9.0/bin/npm i -s

deploy to production server:
  image: node:14.9.0
  stage: deploy
  only:
    - master
  script:
    - cp -r * /the/folder/backend/
    - cd /the/folder/backend/
    - /home/gitlab-runner/.nvm/versions/node/v14.9.0/bin/npm run migrate
    - node_modules/pm2/bin/pm2 reload all --update-env -- DB_OPERATOR_USERNAME=$DB_OPERATOR_USERNAME DB_OPERATOR_EMAIL=$DB_OPERATOR_EMAIL DB_OPERATOR_PASSWORD=$DB_OPERATOR_PASSWORD DB_ADMIN_USERNAME=$DB_ADMIN_USERNAME DB_ADMIN_EMAIL=$DB_ADMIN_EMAIL DB_ADMIN_PASSWORD=$DB_ADMIN_PASSWORD DB_USERNAME=$DB_USERNAME DB_DATABASE=$DB_DATABASE DB_PASSWORD=$DB_PASSWORD

after pushing the master branch and let the pipeline run, it's not loading the 14.9.0 node version.

Checking out b795f45a as master...
Removing node_modules/
Skipping Git submodules setup
Executing "step_script" stage of the job script
$ node -v
v8.10.0
$ /home/gitlab-runner/.nvm/versions/node/v14.9.0/bin/npm i -s

if I ssh into my server, the node version that nvm loads (the default one) is the 14.9.0

I have 2 runners in this machine. The first one for the frontend (and it loads the correct default version of node, which is 14.9.0) and the second one for the backend that has the above problem. The node versions are the same. I don't have docker at the moment and the node -v command inside sudo su gitlab-runner user shows 14.9.0

Why the gitlab runner is loading the 8.10.0 version? how can I set it to 14.9.0?

Thanks in advance