how I can pass a JSON value to 'apex_exec.add_parameter' in 'apex_exec.execute_web_source'.

APEX 20.2

"If I pass a string value, it's accepted. However, when I pass 'log_files' with a JSON value, it's not working as expected. Please let me know how I can pass a JSON value to 'apex_exec.add_parameter' in 'apex_exec.execute_web_source'." I attached code below.

DECLARE

 l_params apex_exec.t_parameters;

 l_response CLOB;

 log_files CLOB;

BEGIN

 -- Check the bind variables

 IF :P3_SET_FILES IS NOT NULL AND :P3_DB IS NOT NULL AND :P3_SR_NUNBER IS NOT NULL THEN

  -- Construct JSON

  SELECT JSON_SERIALIZE(JSON_ARRAY(:P3_SET_FILES)) INTO log_files FROM dual;