How to attach a bracket to a textured surface? 3D panel (made of gypsum) behind the TV.

On the wall (where the TV was supposed to be) are glued and painted gypsum panels (vertical lines). To securely fix the bracket to the wall, a flat surface needs to be made.

We fit the bracket and cut out the relief. But this is quite challenging. First of all, the room needs to be prepared. It will be very dusty, and everything needs to be covered with furniture film. From the available tools, there was a wood router. Using the router and a screwdriver, we drill circles in the gypsum panel. The gaps between the circles are broken using pliers.

When the required area is cut out - we fit the bracket. Probably, the bracket will be too deep and something will need to be placed under the bracket (for example, a fiberboard sheet, or even several layers). In our case - we were short by 1mm for the TV mount to be secured on the bracket. So we added washers to the screws behind the bracket panel. This was enough for everything to work as it should. The gypsum panels are painted, so we painted over the drilling area to hide the white color of the gypsum from certain angles. This is not a 100% good or correct option. But this is our experience of how we installed the bracket and other fasteners on the relief panel using available tools.