Hi,
frictionless support with a tangential traction of 0 in ANSYS is equivalent to symmetry constraint on SimScale. Both fix the displacement in the direction normal to the surface and allow it in tangential directions. If traction !=0 is added an orthotropic elastic support could be used to model this, as @ahmedhussain18 already suggested.
If the surface where the frictionless support should be applied, is orthogonal to any of the coordinate directions, I would advice to use an equivalent fixed value constraint instead of “symmetry”. It reduces the risk of creating an over-constrained system, as explained here: Pin - the problem with contacts - #6 by rszoeke
Best,
Richard