If you are talking about System is Taking Applications then it does have some yuri in it, but it is not the predominant pairing at the moment.

How did you write those yuri scenes (do you have a better/proper word for it)? Even if I want to write it, I will find it difficult to do so. Does it need experience?

So far the only deep romance between a homosexual couple that I've read in a web novel is 'Release That Witch'.

I write them like I would another romance scene. Except the couple are both women. A better word would be a lesbian relationship. Of course every romance is different, but all you need to do is make sure your characters act like your characters in the relationship.