The youngster is expected to move to Everton in the coming days after having a transfer request accepted by Bayern management.
After their preseason friendly defeat to Bournemouth, Moyes said: "We have made an offer.
"Whether it's accepted and whether it's all done... but he's a young player. It's someone we see as having a good future and good potential."
The Toffees have signed goalkeeper Mark Travers, made midfielder Carlos Alcaraz's loan move permanent and French striker Thierno Barry for £27m.
Moyes added, "Well, we've signed three, so if you take that off, we're still in the need of maybe five or six players. That's what we have to try and do.
"I've never had one of these times. In the past I have had to sign a lot of players, but I've never had to do so many in one window."