You wouldn't use an ADB port, LocalTalk used the printer port.

For your SE you could get an ethernet adapter that plugged into the SCSI port or a PDS card to go inside the case.

That too is possible (serial ports though, not ADB). There are existing LocalTalk-to-Ethernet bridge products from long ago that are getting harder and harder to find. I was actually working on a new one for a while but ran out of the time/motivation to finish it up. https://mac68k.info/forums/thread.jspa?threadID=275&start=0&...