what is default value of $PGPASSWORD and how to set a value ?

i saw $PGPASSWORD in https://github.com/supabase/supabase/blob/master/docker/volumes/db/roles.sql

but i could not find value of this variable in https://github.com/supabase/supabase/blob/master/docker/.env.example

what is difference between $PGPASSWORD and POSTGRES_PASSWORD?

what is value of PGPASSWORD

do i have to add and set value of PGPASSWORD in .env file?

GitHub

The open source Firebase alternative. Follow to stay updated about our public Beta. - supabase/roles.sql at master · supabase/supabase

GitHub

The open source Firebase alternative. Follow to stay updated about our public Beta. - supabase/.env.example at master · supabase/supabase