Github Actions Workflow npm acces denied

Question

This is my .yml file

name: Automated API tests using Postman CLI

on: push 
        
jobs:
  automated-api-tests:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Setup Node.js
        uses: actions/setup-node@v2
        with:
            node-version: '16.x'
      - name: Configure npm authentication
        run: echo "//npm.pkg.github.com/:_authToken=${{ secrets.ACCESS_TOKEN }}" >> .npmrc 
      - name: Install dependencies
        run: npm install server/package.json
      - name: Start server
        run: npm install nodemon -g && nodemon server.js &
        # Install nodemon globally and run the server using nodemon
      - name: Wait for server to start
        run: sleep 5
        # Wait for 5 seconds for the server to start up
      - name: Install Postman CLI
        run: |
          curl -o- "https://dl-cli.pstmn.io/install/linux64.sh" | sh
      - name: Login to Postman CLI
        run: postman login --with-api-key ${{ secrets.POSTMAN_API_KEY }}
      - name: Run API tests
        run: |
          postman collection run "20943924-a58169dd-2df0-4d23-a442-ad0872d4ac4b"

I am trying to install dependencies of my server and run the server on github server locally and than test it with Postman CLI.But I am constantly getting the error below.

Run npm install server/package.json
npm ERR! code 128
npm ERR! An unknown git error occurred
npm ERR! command git --no-replace-objects ls-remote ssh://git@github.com/server/package.json.git
npm ERR! git@github.com: Permission denied (publickey).
npm ERR! fatal: Could not read from remote repository.
npm ERR! 
npm ERR! Please make sure you have the correct access rights
npm ERR! and the repository exists.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/runner/.npm/_logs/2023-04-09T13_14_19_023Z-debug-0.log
Error: Process completed with exit code 128.

I have defined a .npmrc file and gave acces to the workflow but I am stil getting the accees error.