Connect pgsql using PHP over web api don’t work

I have a web api script from pos system that works retriving data using a form and submit.

“select sum (antal*pris) from batch_salg where fakturadate = ‘2023-08-25’ “

fetch_from_table($serverurl,$db,$saldiuser,$api_key,$select,$from,$where,$order_by,$limit);

$serverurl="https://somedomain/pos/api";
$saldiuser = 'apiuser';
$db='posdb_9945864';
$api_key='dsdkfswaewmfmkev4546';

I have limited skils in an they are in Mysql, Im trying to get something like this to work

pg_connect(DB_HOST, DB_USER, DB_PASSWORD) or die(pg_error()); 
pg_select_db(DB_DATABASE) or die(pg_error()); 

$sho1_pg = pg_query("SELECT sum (antal*pris)  FROM batch_salg WHERE fakturadate ='$date_today'")
or die(pg_error());  
$shop1_row = pg_fetch_array($sho1_pg);
$shop1_today = $shop1_row['sum'];

First part works and output total sum by items sold * price
Second do not connect to db. strugling to get it to connect using the url and api key
Getting this:

Warning: pg_connect() [function.pg-connect]: Unable to connect to PostgreSQL server: invalid port number: “pos_99” in /var/www/genogbrug.dk/stuff/jk1.php on line 24
Connection attempt failed.