Deploy to a Server on Render.com

Add one of the render.yaml files shown below or use the render recipe
Push code to your GitHub repo
Log in to Render.com
Click on the New + button and then the Blueprint menu item
Connect your GitHub account then select your blitz app repo
Follow the directions on the screen and click apply
Your server + database will be automatically configured and started. Each git push will trigger a new deploy

Without database:

Use this render.yaml:

services:
  - type: web
    name: blitzapp
    env: node
    plan: free
    buildCommand: yarn --frozen-lockfile --prod=false && blitz build
    startCommand: blitz start
    envVars:
      - key: NODE_ENV
        value: production
      - key: SESSION_SECRET_KEY
        generateValue: true

With Postgres database:

Update your render.yaml to provide the DATABASE_URL environment variable to connect to your database:

services:
  - type: web
    name: blitzapp
    env: node
    plan: free
    buildCommand:
      yarn --frozen-lockfile --prod=false &&
      blitz prisma generate &&
      blitz build &&
      blitz prisma migrate deploy
    startCommand: blitz start
    envVars:
      - key: NODE_ENV
        value: production
      - key: DATABASE_URL
        fromDatabase:
          name: blitzapp-db
          property: connectionString
      - key: SESSION_SECRET_KEY
        generateValue: true

databases:
  - name: blitzapp-db
    plan: free