The Lenovo Tab M11 (Wi-Fi only, 11", 128 GB, Luna Grey) does not support video output via the USB-C port. This means that you cannot connect it directly to a projector with a USB-C to HDMI cable to play a PowerPoint presentation. The USB-C port is only used for charging and data transfer.

Alternatively, you can use wireless transmission methods such as Miracast or Chromecast, provided the projector or a connected device supports them.