If you can't find an internal bonnet release, I suspect that it's one of the Ford models where you go to the front of it, rotate the badge to reveal the bonnet lock, insert your ignition key, turn it one way and then turn it the other.
On my old Focus you just flipped the Ford badge clockwise on the front of the bonnet to access the keyhole where you insert your key to release the bonnet catch by turning the key one way and then the other way. Don't forget to return the badge after closing the bonnet.
Many thanks chiaroscur - so it is ! What an odd place to put it.
My Mondeo has the flippy badge that you lift up and use the key
I would have looked for ever to find that !