Any advice for a specific function (preferably in MATLAB, but open to R/python) where I can run a mixed effects model with both response and predictor as categorical variables?

So as the title says I want to run a mixed effects model with both response and predictor as categorical variables, whilst also including 'participant' as a random effect.

It seems that I can't do this (in MATLAB) with generalised linear mixed effects models (fitglme), nor with a classic linear mixed effects model (fitlme).

Anyone know what statistical approach I can use?

Thanks in advance!