Setting up a definite spawn point for FirstPersonController in Ursina

I have two questions.

• I want to set my FirstPersonController() to spawn at a definite coordinate. How can I do that ?
• When I run a Ursina code with FirstPersonController(), it seems to be locked in a position or falling into void, but I had set up a floor of cube. How can I fix it ?

The FirstPersonController can be given a position:

player = FirstPersonController(position=(10, 0, 10))

This is also documented in the ursina cheat sheet.

If you can't move around you may be stuck inside a block. Try using space to jump out. In case you're falling through the ground you may have forgotten to set a collider on it. Please show your relevant code.