Your wall surface is plasterboard. There's a gap behind. The board is fixed to the block via either battens or blobs of plaster adhesive. Either way, most of the plasterboard surface is unsupported, so you're not going to fix directly to it. You're going to use a product to anchor in to the block and then provide some way of bridging the gap so it transfers the TV weight to the wall. Rigifix is one example.
You'll drill or cut holes in to the plasterboard but avoid going deeper than the board thickness. Once you can see in to the space then simply move the cables to one side to drill in to the wall proper.
Was just scrolling through my photos (I have taken hundreds) and found one I forgot I took. That'll help! I should be able to find some clear spots each side of the cables.
Depending on the size of your bracket if i was in that situation I'd offer the bracket up and mark all fixing points. I'd then carefully cut a hole/holes in the plasterboard away from the fixing points but in a position where they would be covered by the bracket so you can inspect behind.
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