navsyncdb, hstore extension and superuser

Trying to upgrade my database from 3.15 to 4.1.1.

I see that the script tries to connect as user 'root' while "Creating hstore extension":

Creating hstore extension in database nav psql: FATAL: no pg_hba.conf entry for host "129.242.5.180", user "root", database "nav", SSL off Failed to install the hstore extension, maybe you need to run as the postgres superuser?

I can of course edit my pg_hba.conf but it will not help since my postgres superuser is 'pgsql' not 'root'.

How can I make the script connect as user 'pgsql'?

or

Can I instead run some sql by hand?

--Ingeborg