3.3V IO with PR1-10 4-Channel I2C Relay Controller (MCP23008)

I have a PR1-10 board (4-Channel General Purpose SPDT Relay Controller + 4 GPIO with I2C Interface), and I would like to know if the I2C IO is 3.3 VDC compatible? The MCP23008 appears to support 1.8-5.5 VDC, but I couldn’t find any detailed documentation on the PR1-10 board that describes the electrical ratings of this board.

If so, would I hook the I2C 5 VDC input on the PR1-10 to a 3.3 VDC supply, and communicate over I2C using 3.3 VDC compatible IO?

Is there any more detailed documentation on this board that describes the different inputs/outputs and their ranges or even a schematic?

The I2C is pulled to 5V and also powered using 5V. I will not recommend directly connecting to 5V.
a level shifter is recommended between 3.3V and 5V