What is the right syntax for retrieving the last_insert_id() in Postgresql ?

Hi,

I hope I am posting on the right forum. I googled but I can't find any solution pertaining to my problem.

Could someone know what is the syntext for last_insert_id() in Postgresql for me to insert into my sql execute query?

public int getTutorById() {
openConnection();
int tutor_id = 0;
try {
Statement stmt3 = connection.createStatement();
ResultSet rs = stmt3.executeQuery("SELECT last_insert_id() from xtutor");
{
while (rs.next()) {
tutor_id = rs.getInt(1);
}
}
} catch (SQLException e) {
e.printStackTrace();
}
return tutor_id;
}

org.postgresql.util.PSQLException: ERROR: function last_insert_id() does not exist
Hint: No function matches the given name and argument types. You might need to add explicit type casts.
Position: 8
at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2440)
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2183)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:308)
at org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:441)
at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:365)
at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:307)
at org.postgresql.jdbc.PgStatement.executeCachedSql(PgStatement.java:293)
at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:270)
at org.postgresql.jdbc.PgStatement.executeQuery(PgStatement.java:224)
at daoMySql.tutorDAOImpl.getTutorById(tutorDAOImpl.java:202)
at daoMySql.tutorDAOImpl.getAlltutors(tutorDAOImpl.java:161)
at business.manager.getAlltutors(manager.java:99)

The generated id is successfully generated by JDBC.

The errors when I tested in out using PGAdmin4 is

ERROR: function last_insert_id() does not exist
LINE 1: SELECT last_insert_id() from xtutor;
^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
SQL state: 42883
Character: 8

Postgresql 11, Windows 11

Thanks.