I don't think the option is available yet, but it has been requested and TGC has indicated they could add the ability to specify the render path:
https://github.com/TheGameCreators/AGK-Studio/issues/372
Developers certainly need a way to provide different rendering paths to their customers considering the benefits and limitations of each. Requests have also been made to provide a 'software' rendering mode displaying text only so server apps can be developed (Tier1) without the need for 3D graphics hardware. A built in command option would be best, such as:
SetRenderingMode(Num)
Where 'Num' could be 0 for software/text only, 1 for OpenGL, or 2 for Vulkan. And even if the bound display device had to be reset to activate the required device, a command option could still work. That is, if Studio dropped to OpenGL or software because required hardware/drivers were not detected (dropping to OpenGL being already automatic), the manual command mode would enable the new render path and device activation on demand as needed. The developer would just need to be aware that they would always have to decrease the render mode from whatever Studio started at (you could go from default Vulkan to OpenGL, but not the other way around) and have the command at the beginning of their game/app before they did anything else.