This is one of the Keyboards that you have to use the propritoary dongle that came with it, it isn't bluetooth.
The UGREEN Wireless Keyboard KU004 is a versatile and compact keyboard designed to enhance productivity across various devices. This keyboard offers a wireless 2.4GHz connection, ensuring stable and responsive input. Its sleek and minimalist design complements any workspace, while the scissor-switch key design provides a comfortable and quiet typing experience. With multimedia shortcuts, it allows convenient control of music and other functions.