I2C Slave on TinyFPGA BX


I found out about the TinyFPGA Boards a short time ago. Now I implemented a minimal CPU on a Breadboard with the use of a TinyFPGA Bx Board.

Sadly, I am failing on an i2c-slave module. Looking online, I started by using this instruction and go from there: https://www.fpga4fun.com/I2C_2.html
But I couldn’t get it to work and also (I believe) that 1’bz (high impedance) is not supported?

Does anyone have a working i2c slave module that is working on the TinyFPGA Bx Board?

If anybody has an advice, he/she would save my day =)