source database "template1" is being accessed by other users for postgresql

sudo -u postgres psql template1

CREATE DATABASE sportizen_development TEMPLATE template0;

Database template1 exists only to provide barebone structure to create another empty database. You should never logon to template1, otherwise you will have problems.

Probably easiest solution for you is to restart PostgreSQL server process, and logon again. Database that should always exist and is safe to logon is postgres.

If restarting is not an option, you can use another emergency template database: template0.

By default, this statement:

CREATE DATABASE dbname;

is equivalent to:

CREATE DATABASE dbname TEMPLATE template1;

If template1 is not available or corrupted, you can use template0 as last resort:

CREATE DATABASE dbname TEMPLATE template0;

You can read more about template databases here

In Short: CREATE DATABASE works by copying an existing database. PostgreSQL won't let you copy a database if another session is connected to it. If template1 is being accessed by other users, CREATE DATABASE will fail.