Sorry, but there isn't a way to turn on interactions for an ACA exercise in our software. I'm guessing that technical paper is referring to doing some reworking of the data where instead of treating something like 10 respondents answered 10 questions, you rework the data so it looks like 1 respondent answered 100 questions and you estimate a single set of utilities for everything. Since ACA is a partial-profile method, the data would be very sparse for looking at interaction effects, so I'm guessing this is probably the only way to do it.
In general modifying ACA data is very, very messy and not something I would recommend to someone.