at that moment in English:

I’m busy at the moment.

I`m doing my homework at the moment.

Betty is cooking at the moment.

There's too much going on at the moment.

I can't speak to you at the moment.

We are very sorry, but the book is not available at the moment. You could come back next week. Chances are we will have it.

I wonder what they are doing at the moment.

What are you reading at the moment?

I've got a lot of work at the moment.

She can't go to the cinema with us, because she is busy at the moment.