Posterior predictive check and package bayesplot

[CWR-05]

Hello,

I have a very general question: I've spent the last hour and half looking on internet for an answer, and I can't find even a hint.

I ran a list of models, very similar to the alligator example and I wanted to do some posterior predictive checks, similar to what is offered in bayesplot. I can't find a tutorial or an answer on stackoverflow, to help adapt the bayesplot functions to a MixSIAR model. Even chatGPT failed to help in finding a solution that works. Based on chatGPT's answers, though, I wondered if the problem comes from the fact that we have k columns of data (k isotope values). I'm at a loss, here.

Is there a way to get and plot bayesplot-like posterior predictive checks for MixSIAR models?

Thank you,
Chloé