Oracle Substitution variables are not supported in the Custom Menu PL/SQL block.

It works in the TEST window only.

There is a workaround for this issue. You would need to,

• Create an IFS SQL Quick Report that prompts for one or more values.
• The Quick Report needs to be composed of a SELECT statement, so the code you call needs to be a function and not a procedure.
• You can create a PL/SQL function that performs many of the operations available in a procedure, such as insert update, delete, calling another package, etc. There are some very specific ways this needs to be done in PL/SQL so it works as expected.
• Create your custom menu that calls your new Quick Report.

You could set up a custom field and have the user enter the data into it before doing the RMB. The RMB could then read the custom field.

Seems working on APps10 UPD11

DECLARE
   p0_ VARCHAR2(32000) := 'START_EVENT'||chr(31)||'40'||chr(30)||'ORDER_NO'||chr(31)||'R42667'||chr(30)||'ONLINE_ORDRSP_PROCESSING'||chr(31)||'FALSE'||chr(30)||'MEDIA_CODE'||chr(31)||'MHS'||chr(30)||'PRINT'||chr(31)||''||chr(30)||'END'||chr(31)||''||chr(30);
cursor c1
is 
select distinct s.source_ref1
from renc1app.SHIPMENT_LINE s
where s.shipment_id= &SHIPMENT_ID;

BEGIN
  
for i in c1
  loop
    p0_  := 'START_EVENT'||chr(31)||'40'||chr(30)||'ORDER_NO'||chr(31)||i.SOURCE_REF1||chr(30)||'ONLINE_ORDRSP_PROCESSING'||chr(31)||'FALSE'||chr(30)||'MEDIA_CODE'||chr(31)||'MHS'||chr(30)||'PRINT'||chr(31)||''||chr(30)||'END'||chr(31)||''||chr(30);
    
   RENC1APP.Customer_Order_Flow_API.Start_Print_Order_Conf__(p0_ );
 end loop;

END;