I’m off-topic, but there’s one particular reason that I encourage people to upgrade from OH2: the log4j vulnerability that was only patched in OH3.
You might want to give a fresh OH4 a try. You should be able to copy your text files into a clean installation and make a few edits to get it all working exactly the same as before (if not better). If it’s too much hassle, you can just go back to your OH2 installation.
Alternatively, you can set up OH4 on a different server and use the Remote binding to access your OH2 server while transferring things over.