It looks like you're new here. If you want to get involved, click one of these buttons!
is this feature going into JASP?
Yes, both in classical and in Bayesian form. The work is done (!), but I am not sure whether it will be in the upcoming release (which we are going to test now) or the one after that. In the mean time, if you want to run the frequentist test (which I strongly dislike, but OK), you can simply look at the 90% confidence interval and see whether it falls inside the area of equivalence.