Rico RGB Keypad Base, assign uart pin

Hello, I bought a Pico RGB Keypad Base. I want to assign a uart pin to this base. However, I am concerned that a uart pin is already being used to connect each button. Is it possible to allocate a uart pin and connect it to an external raspberry pie?

The buttons are connected to an IO expander which then connects to the Pico via i2c.
And the LED’s only use a couple of the SPI pins. You have oodles of pins to use for other things.
There is a link to the schematic on its shop page. ;)
pico-matrix-keypad.sch (shopify.com)

then can I use the pin 1,2 for assigning UART pin?

Yes, you can use pins 1 and 2 fort assigning to UART.

Thank you!
I’ll try it