Hi there,
it has been a while since I checked this place the last time. Sorry for keeping you unanswered!
I found a couple screenshots, hope it helps. The SAP system language is German, but I'm confident you will be able to deduce or translate the necessary content.
1. Create a new ALE-Interface for BAPI in Transaction "BDBG":
2. Configure:
3. Release:
You will need a developers key to release. I'm afraid that i cannot help any further in creating new ALE for BAPI. Hopefully it's enough Information for you.
Kind regards,
Pascal