The rails program does not create a database even though typed the code correctly?

I am newbie with rails and trying to create a new rails program with postgre database by this command rails new freelancer --database=postgresql

I typed it very carefully and I hoped that I could have a rails program with a database which configure in a database.yml file (something as they said on internet which I can connect to postsql).

But, my problem is, when I open my database.yml, here it is

default: &default
adapter: sqlite3
pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
timeout: 5000
development:
<<: *default
database: db/development.sqlite3
test:
<<: *default
database: db/test.sqlite3
production:
<<: *default
database: db/production.sqlite3

I do not know why it does not create the database for me as they said (they said that, if I use that command, the database could be created and will be created witl name freelancer_development which can be display in this file ?

Could you please give me some ideas ? Thank you very much for your comment.