Deploy to a Server on Render.com

Add one of the render.yaml files shown below
Push code to your GitHub repo
Log in to Render.com
Click on the "YAML" menu item, then click the "New from YAML" button
Connect your GitHub account then select your blitz app repo
Click approve
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: starter
    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: starter
    buildCommand:
      yarn --frozen-lockfile --prod=false &&
      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: starter