I have a problem when I am deploying in Heroku:
/app/vendor/bundle/ruby/2.6.0/gems/bundler-1.17.3/lib/bundler/rubygems_integration.rb:408:in `block (2 levels) in
Heroku doesn't natively support SQLite3, and although I see you added the pg gem in production, you'll also need to configure your Rails application to load its database from PostgreSQL by editing config/database.yml to connect to PostgreSQL.
pg
config/database.yml