There is a 2d one in the ArchiCAD 13 Library plus there is a 3d one from CAD Consult
As for a Platform lift I can't remember seeing one but the one time I had to draw one I did it as a slab and a complex profile for the handrail.
As you haven't put your ArchiCAD version in your signature I'm not sure if the above helps!
AC versions 3.41 to 25 (UKI Full 5005).
Using AC25 5005 UKI FULL
Mac OSX 10.15.7 (19G2021) Mac Pro-2013 32gbRam AMD FirePro D500 3072 MB graphics