Having Trouble Enabling pg_stat_statements to Enable Heroku pg:outliers

I am trying to run the pg:outliers command in the Heroku command line tools and I am getting the following error:

 ▸    pg_stat_statements extension need to be installed in the public schema first.
 ▸    You can install it by running:
 ▸    
 ▸    CREATE EXTENSION pg_stat_statements;

I ran "CREATE EXTENSION pg_stat_statements; in my Postgres database and verified that it is there with psql -d database_name -c '\dx' which shows:

                                            List of installed extensions
        Name        | Version |   Schema   |                              Description                               
--------------------+---------+------------+------------------------------------------------------------------------
 pg_stat_statements | 1.8     | public     | track planning and execution statistics of all SQL statements executed
 plpgsql            | 1.0     | pg_catalog | PL/pgSQL procedural language
(2 rows)

But when I run heroku pg:outliers I still get the above error saying I don't have the extension installed in the public schema.

I must be misunderstanding the instructions to install it but I can't find anything clarifying the process that would indicate what I am doing wrong.

Can anyone see what I am doing wrong to get this extension to run properly? Thanks for any insight!