Hello,
The one you mentioned, the L476JC, is not in the microcontrollers that we officially support. On the other hand, we support L4R9, L496G as well as L4P5G.
If when you select this MCU (L476JG) you have the possibility to add the TouchGFXGenerator Package and use it for this microcontroller (I personnaly never done it), then you could use TouchGFX but you'll have to do most of the development yourself.
/Alexandre
