ᐅ 2 faucets, but only one water supply and drain connection

Hello everyone.
In our bathroom, there is only one pipe in the wall.
However, we have a washbasin that requires two faucets to be installed, as it has two faucet holes.
During the construction phase, we bought the washbasin, but only one pipe was installed at the same time.
Soon the washbasin will be installed by ourselves.
What options do we have in this situation?
So far, I haven’t found any connection solutions that convince me.

No idea... what does the plumber say?

Hmm...

T-pieces are very helpful in this case.

It’s not KNX, or were you expecting a star topology for water and wastewater?
I think I didn’t fully understand the question.

Is everything already plastered and tiled, and this is only now being noticed?
If not, see @Mycraft

Yes, the pipes are installed so far.
We purchased the washbasin ourselves and told the plumber at the beginning that we would install it ourselves. Therefore, he will not handle it.
I have not found a suitable T-piece yet.
I always only find parts with a small drain on the side. Usually, a hose is connected to that. At least, not a plastic pipe with 32 or 50mm (1.25 or 2 inches).
I want to avoid using flexible hoses in this setup. However, probably due to space constraints with all the pipes, I might not be able to avoid it.

Is there also a kind of flexible siphon?

So, I would suggest you start by taking a photo of the situation.