Create a receiver, then a journal, then journal each file:
CRTJRN JRN(lib/jrn) JRNRCV(lib/rcv0000)
STRJRNPF FILE(file1 file2 etc) JRN(jrn)
but before you do any of that, read up on journalling and make sure you understand the implications. Journalling, and it’s partner Commit Control, can be a great for building robust applications but done wrong can cause problems.
Also if possible I recommend keeping the journal receivers on a separate ASP.