Help! gpu acceleration not working

I have AMD Radeon R9 290x (4gb memory) connected to my system but won’t be able to render with GPU… Please help me resolve this problem.
motherboard: ASROCK N68-GS4 FX R2.0
CPU: AMD FX-8350

Sketchup version: 2019
Vray: 4.0

Vray GPU works only with Nvidia GPU.