Opening of plank outer wall

[Glenntan]

I am planning to open up an exterior plank wall.
It's one of the gables of the house. The opening is supposed to be 3m for a facade section that will be installed.

So, I'm reaching out here to see how I should proceed.
I've been thinking about it myself and trying to find a carpenter, but unfortunately, I can't get any help until next year.

I was thinking of embedding a glulam beam in the plank wall just above the line drawn on the plank. The question is whether I need to use temporary supports and where I should place them if that's the case?
The last floor joist beam is about 60cm from the exterior wall. So the floor on the upper floor is probably attached to the exterior wall.

Does anyone have some advice to make sure it turns out right?
I am attaching pictures of the interior wall as well as the exterior.
The section should be installed under the red brick lintel.

 

[16386]

It does vary between municipalities, but doesn't the municipality require a construction drawing in the building notification? Or in other words, don't you need to hire a structural engineer? (Now I've assumed that the property is covered by a detailed plan - I think it looks like you have a neighbor nearby.)