Application of facing stones, is a mesh mat mandatory or optional?

Good morning everyone.

We have built a terrace partition wall from calcium silicate bricks. We now want to beautify it with facing bricks.

After the wall has been primed, the question arises whether a mesh must be "embedded" or if the priming is sufficient when the facing bricks are glued on afterwards.

No idea, but if you're unsure, just put one in, costs nothing