How can I backup MacBook before the battery runs out?
This adapter will help you. Also useful for other use cases.

The USB-C Digital AV Multiport Adapter lets you connect your USB-C or Thunderbolt 3 (USB-C) enabled Mac to an HDMI display, while also connecting a standard USB device and a USB-C charging cable.



Or this one:
HyperDrive USB Type-C Hub with 4K HDMI Support

Matching colours. Turns a single USB Type-C port into 4 ports (HDMI, 2 x USB 3.0, USB Type-C with Power Delivery)