How to pass the variable in postgres using dbblink

Oops, good morning!

I have the following query in postgres:

declare $1 VARCHAR;
    BEGIN
         IF 
        (SELECT COUNT(*) FROM tempo2
            WHERE looping IS NULL) > 0
            THEN
           $1 = (SELECT banco FROM tempo2 WHERE looping IS NULL LIMIT 1);
INSERT INTO...
       SELECT * FROM dblink ('host=xx.xx.xx.xx dbname='||$1||' 
                                 user=xxxxpassword=xxxxx',
        'SELECT ... 

My problem is that the database is not reading the variable '|| $ 1 ||', I believe that when it is read in SELECT the contents of it already come with '(single quotation marks), example: SELECT * FROM dblink (' host = xx.xx.xx.xx dbname = '' variable '' ...

Can anyone help me?

Abs, Lucas.