What are the default I2C1 pins on the Pico Lipo?

[donmerch]

I found that GP4 and GP5 are default for I2C0 and STEMMA connector but haven’t found info for I2C1.

[alphanumeric]

I would say that since i2c 1, isn’t being used, it’s not defined?
The Stemma connector (i2c 0) is hard wired and needs to be setup to use those specific pins. i2c 1 isn’t being used and doesn’t have a default. You set it up to use the pins you want to use. As per the pinout.