In my opinion, it may have to come off. It could be that the bracket needs attaching to it, or behind it.
However. It appears to me because of the aerial location, that a bracket is intended to go there. I imagine that it was originally an option.
If so, there will be a method to do it. And it is likely designed for a specific bracket. (which will be at a premium price).
Ask a dealer. There is no reason why they will not advise you. You will then be free to get your own bracket and fit it yourself if you want to.
I would search on YouTube for “elddis tv bracket mounting instructions”.
Here is an example.
View: https://youtu.be/2RpoPOjz0k0?feature=shared
John