Is there a way to make a creature larger than 4x4 on the VTT?

In an upcoming session I am having, I plan on having Enlarge being cast on a creature that is already gargantuan who then drinks a potion of growth, making them grow 2 sizes. Is there a way to make creatures larger in the vtt than just the standard 4x4? if not, are there any suggestions on how I can achieve this effect on DnDbeyond's vtt?

By RAW, I don't think creatures can get bigger then Gargantuan, since Gargantuan is the largest size category. If you want to go outside the rules, you could try grouping the creature token to an overlay of the desired size.