Use a spade drill bit to drill about 30mm into the three marks you’ve made on the post. Then use a wood drill bit, to drill into the three holes in the post but don’t drill into the bricks. Do this by making a mark on the drill bit at the depth you want to drill. Using a masonry drill bit, drill through the post and into the bricks. Hammer the Dynabolts into the holes and use a socket wrench to secure the post against the wall.