How to fix marker and radius in center in google maps?

I want to fix the marker and the radius of it in the center of the map irrespective of the location coordinates. If the user moves the camera on map I want it to keep showing up in the center without any flickering in radius or the marker and user should be able to increase and decrease the radius. How can I do that? Please help out. Thanks

If this is a question about a third party framework (Google Maps) then you'll have to ask on a different forum. Only Apple tools and APIs are allowed to be supported here.

Okay.

How to fix marker and radius in center in google maps?
 
 
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