Trying to make return works

pgsql-schema.sql

@@ -84,6 +84,8 @@ CREATE OR REPLACE FUNCTION INSERT_CT(
                 IN _ct_event integer
         )
 RETURNS bigint AS $$
+DECLARE _id bigint;
+BEGIN
         INSERT INTO ulog2_ct (ct_id, oob_family, orig_ip_saddr_str, orig_ip_daddr_str, orig_ip_protocol,
                         orig_l4_sport, orig_l4_dport, orig_raw_pktlen, orig_raw_pktcount,
                         reply_ip_saddr_str, reply_ip_daddr_str, reply_ip_protocol,
@@ -92,8 +94,10 @@ RETURNS bigint AS $$
                         flow_start_sec, flow_start_usec,
                         flow_end_sec, flow_end_usec, ct_event)
                 VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14,$15,$16,$17,$18,$19,$20,$21,$22,$23,$24);
-        $1;
+        _id = $1;
-$$ LANGUAGE SQL SECURITY INVOKER;
+        RETURN _id;
+END
+$$ LANGUAGE plpgsql SECURITY INVOKER;
 
 CREATE OR REPLACE FUNCTION INSERT_OR_REPLACE_CT(
                 IN _ct_id integer,