Of course. Just take the ordinary, reservation free IC-train. Leaves at +/- hh:45, every hour, from Brussel Zuid/ Bruxelles Midi (resp. 5 & 10 min later in the Centra(a)l en No(o)rd stations of Brussels - which is often more convenient, depending on accomodation)

Change in Rotterdam (or Breda).

That was what I was hoping but can’t see it on the timetable? All I get are options to change at Rotterdam.  Let me try again.

Updated my post. Every hour +/- hh:45.

Use www.bahn.com to plan, de-select High Speed trains via the Further Options to see the right results.

And by the way you don’t need any extra fee for this, should the rail planner app tell you that.

Thank you - that’s now worked.