You need a version that has logical decoding enabled. Use docker:
docker run -p5432:5432 --name postgres94maps -d sebastianharko/postgres94
Connect to database using (some GUI).
port = 5432
host = localhost
database = pgdb1
user = pguser
password = pguser
DROP TABLE IF EXISTS "public"."users";
CREATE TABLE "public"."users" (
"id" int4 NOT NULL,
"lat" float8 NOT NULL,
"lng" float8 NOT NULL
);
ALTER TABLE "public"."users" ADD CONSTRAINT "users_pkey" PRIMARY KEY ("id");
sbt run
Open browser at http://localhost:8080/map.html
Insert a random user:
INSERT INTO users VALUES(floor(random()*1024), floor(random()*(40-25+1))+25, -1 * (floor(random()*(120-80+1))+80));