SP2-1506: START, @ or @@ command has no arguments

Oracle 19c on AIX ncruxdb353 

I`m creating a bash script, within that script I use a sqlplus command to verify that I`m in the correct PDB before running a script.

SET SERVEROUTPUT ON SIZE 1000000;

DECLARE

l_script varchar2(150);

  pdb_name varchar2(20);

BEGIN

l_script := '/home/oracle/scripts/auto_scripts/OCI/PROSA/cr_tbs_script.sql';

  SELECT name into pdb_name FROM v$pdbs;

case pdb_name

WHEN 'PROSA' THEN

    l_script := '/test/cr_tbs_script.sql';

END CASE;

DBMS_OUTPUT.PUT_LINE( l_script );

END;

/

@&l_script

When I run it, the DBMS_OUTPUT show the proper path for the script. But when it tries to run it, it request for the value of l_script and then error SP2-1506: START, @ or @@ command has no arguments