How to use the GitHub actions to add a comment in PR

In GitHub api, there is an api to create an issue comment. I want to use it in the GitHub actions CI/CD pipeline.

I create the workflow.

name: Workflow

on:
  push:
    branches:
    - main
  pull_request:

jobs:
  test:
    name: Test
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2

      - name: Run jest coverage and log the result to GitHub summary
        run: |
          npm run test-coverage >> $GITHUB_STEP_SUMMARY
          echo "UNITTESTCOVERAGE=$GITHUB_STEP_SUMMARY" >> $GITHUB_ENV
          echo "" >> $GITHUB_STEP_SUMMARY

      - name: Post jest coverage comments
        env:
          PR_NUMBER: ${{ github.event.pull_request.number }}
          REPO: ${{ github.repository }}
          SUMMARY_URL: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}
        run: |
          curl \
            -X POST \
            -H "Accept: application/vnd.github.v3+json" \
            -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
            https://api.github.com/repos/$REPO/issues/$PR_NUMBER/comments \
            -d '{"body":"# Job Summary\n'$SUMMARY_URL'\n'$UNITTESTCOVERAGE'\n"}'

  deploy:
    ...

Instead of showing the jest coverage result, GitHub bot add the comment.

Job Summary
...

/home/runner/work/_temp/_runner_file_commands/step_summary_d0****01-f**9-4**7-b**7-f0******dc3f

How to do get the actual result?

Update 1

I removed unrelated steps to make it clear.

Response

Update 2

I set jest --coverage to create coverage report in text format (and other formats, not important here), and I want to create a comment to show the text format report.

In package.json, I added npm run test-coverage to run Jest coverage report. Therefore, npm run test-coverage will print the result in terminal.

I used npm run test-coverage >> $GITHUB_STEP_SUMMARY to redirect the result to GitHub step summary, so I could see the coverage report in GitHub step summary.

I wanted to use GitHub api to create a comment to show the coverage report in the PR. I used echo "UNITTESTCOVERAGE=$GITHUB_STEP_SUMMARY" >> $GITHUB_ENV to set environment variable UNITTESTCOVERAGE to be $GITHUB_STEP_SUMMARY, and I wished UNITTESTCOVERAGE can get the coverage report.

However, the step Post jest coverage comments could not get the coverage report. Instead of the report, the comment created by GitHub api showed a file / directory path.

How to add the coverage report to a comment by GitHub api?