Maybe try some codes from here?

[Link: files.remotecentral.com]

I just googled for Pioneer steez ir codes and found a hit that took me to a pioneer site.

[Link: pioneerelectronics.com]

I selected Music Systems and Network players and found 4 links with spreadsheets that have the Raw Pronto Hex Codes for various functions.

Give them a try.

I can't find really anything other that what I've shared above. I did find the manual online but it does not even indicate if the remote is IR. It simply says wireless remote. However, since Bluetooth was not prevalent back in 2012, I'd say it is likely IR.

Do you not have the remote you can learn?