A reflexion probe is a tool close to a 360Â° camera you'll place in 3D space in order to get visual information to plug it into a renderer.
Is here the procedure to follow in order to enhance reflexions:
1 - Create a Reflection Probe (right clic->reflection Probe).
2 - Add an environment map into your Surface
Renderer (right click on the surface renderer).
3 - Change the environment map component into "Reflection Probe" (a preset of the environment component allows to create it directly, go check the Use presets
part of the doc).
4 - Select the Reflection Probe map and just drag and drop the probe into it.
Here is a result of this tool: