Find_MAP when optimizing a Potential

Thank you that works, however what is the “samples” argument in the compiled dlogp?
In general samples is not observable in my case.
I was thinking that model.compile_dlogp(vars=[p]) would give the gradient of the posterior distribution with respect to a variable p, under the assumption that the prior is sampled from the uniform distribution.
Is it instead the posterior distribution assuming an observation for samples?