I am using Turborepo with 3 apps,
I have a CI/CD pipeline for preview deployment
How can I update my .env variables such that each app has access to its preview URL as well as the other 2 preview URLs?
For its preview URL, I can make use of VERCEL_URL, how can I get access to the other preview URLs from an app?

if the preview URL can only be accessed after a build completes, I would need to do another build to update the URL, maybe the new deployment will have a different URL. but, I don't want to build the same thing twice anyway.

Note: I don't want to use vercel alias, as I need a unique URL for every PR.

name: Vercel Preview Deployment
env:
  VERCEL_ORG_ID: ${{ secrets.VERCEL_ORG_ID }}
  VERCEL_PROJECT_ID: ${{ secrets.VERCEL_PROJECT_ID }}
on:
  push:
    branches-ignore:
      - main
jobs:
  Deploy-Preview:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Install Vercel CLI
        run: npm install --global vercel@latest
      - name: Pull Vercel Environment Information
        run: vercel pull --yes --environment=preview --token=${{ secrets.VERCEL_TOKEN }}
      - name: Build Project Artifacts
        run: vercel build --token=${{ secrets.VERCEL_TOKEN }}
      - name: Deploy Project Artifacts to Vercel
        run:  echo preview_url=$(vercel deploy --prebuilt --token=${{ env.VERCEL_TOKEN }} --cwd apps/web) >> $GITHUB_OUTPUT

      - name: Print preview url 
        run: echo ${{ steps.deploy.outputs.preview_url }}