Hi @IsaacFH,

There is a similar question from a user which was also using App Platform with Angular again experiencing a 404 error:

https://www.digitalocean.com/community/questions/app-platform-app-reloading-leads-to-404-site

• download current app spec from https://cloud.digitalocean.com/apps, in the settings tab you will find App Spec to app.yaml file

• add catchall_document: index.html

  ex:
  name: myapp
  region: fra
  static_sites:
  - build_command: |-
    npm install
    npm install -g @angular/cli@11.2.0
    ng build --prod
  environment_slug: node-js
  gitlab:
    branch: master
    deploy_on_push: true
    repo: myrepo/myapp
  name: myapp
  output_dir: dist
  catchall_document: index.html
  routes:
    - path: /
  

• find app id by running: doctl apps list

• update spec by runing: doctl apps update {{ap_id}} --spec app.yaml

Having said that, I’ll urge you to check out the question and the thread beneath it, it might help you further.