Most likley you need a SS bracket that from one side attaches to the boat and have a pipe in which the end of the passarelle fits - you can buy one of-the-shelf or get one made by local SS shop ... on all my boats in the end I needed to get one localy made...,
Fyi: Also the easier and safest way is just to ise plank instead of passarelle..
My one is not 469 ... a lot more miserable Sun Liberty 34 but still you can see how my bracket looks like - I specially designed it to be able change angles directions almost anything... and been able to fold the passarel and still hang the dinghy on the davits
We have been fiddling with getting the system to work over the past season since arriving in the Med.
Main issue was as I fitted it off centre as I didn't think the steps would have been strong enough, but that meant that the side support guys only worked in one direction. You can see this from the photos, so I was having to tie the passerelle off on the quay to stop it swinging etc
But now have ditched the side guy lines and use a telescopic pole with small spi fittings which as a push-rod so the passerelle can be adjusted to almost any angle. This works pretty well.
I also initially used the topping lift with a bracing bar to support the end, but now have simple 6:1 tackles from the solar panel support, which is also much better. The above photo was taken last month as we are laid up afloat in Valencia. I now simply swing the passarelle across the transom, it fits fine and that also means no need to remove stanchions etc
I also fitted larger wheels, which can be just seen in the photo above and also some sacrificial rub rails for when we moor to concrete breakwaters. The Oscualti bracket is maybe a bit low, it it was higher the passerelle would be at a better angle and the original wheels would have then been fine, but stepping onto the bathing platform would probably be more awkward.
Finally saw this hydraulic Besenzoni being fitted to a 43DS, they had issues with the stern flexing as it is obviously very heavy www.besenzoni.com/passerelle/. Hopefully they ended up putting in some major reinforcement.
I've not been needing a passarelle much with the fold down stern platform but occasionally it's good to be a bit further off the dock so just need to look at fitting a stainless pipe/hole in to the stern platform to receive the male part of the passarelle.
Can never understand why the manufacturers don't offer a variety of brackets to suit all needs and why they expect you to get bespoke from a third party.
No such problems of flexing on our 43DS but we are not hydraulic. It was however a pig to install as there is no easy way to access the back.
Do not compromise and go for a design that won't pivot. It is guaranteed that you will always be placed on the quayside with an electricity box in the way!!!
Getting the right right length to suit you is also important. Too long and it will intrude onto a pontoon or you have a lot of water to cross to get ashore. Too short and you are always a bit close in.
Gang Planks are safer!?! Having been thrown into the water by one that move/slipped in wake I tend not to think so. I still have scares to remind me. Also they are very heavy and cumbersome.