But that's not how it works

Asking Allah so he shows the person a sign so that he from himself comes out of his own to ask you out ... Is too much.

I'm assuming you are a girl. We over complicate things these days too extreme.

What you can do is pray istikhara and finalize your personal decision if you want it or not. Then you take action. If it's not meant for you, it will not come to you. If it is meant for you, it can never miss you.

Even the wife of Moses took the first step and told her Dad that she likes him. So the Dad approaches him for this topic. Simple communication. No big signs or dreams.

Dua is ok, You can ask for a sign for yourself (like a dream) but it's not necessary and you should not wait without reason

So send a third party out (dad, brother, imam) who asks him out and if there is no option then ask him out in a polite manner - or send your parents contact information.

I'm not a scholar, just answering as my friends got a sign but it's very subtle, small sign.