If you look straight down to the right of the tube, there's a 17mm bolt labelled ATF. You need a long socket extension to get it off. Once off, you'll need to move some vacuum tubes around in order to get a long funnel in there.
If it is an automatic you probably fill it through the dip stick tube. There are special funnels, available at auto stores, for this function.
I had try to fill into that tube, but the tube too small , that should be another place to fill in, this is a Honda vehicle ( not same like another branch, that they have a large dip stick tube for auto transmission ).