# Generating R squared statistics when carrying out a Firth Logistic Regression

I am using the logistf package available for SPPS to carry out a firth logistic regression, and have results relating to the coefficents, standard errors and p-values associated with each predictor. I would now like to calculate the R square statistic associated with the model (preferably McFadden’s) in order to make some assessment of model fit, and to contrast model fit when particular variables are added in or removed. However, the output from the logistf package doesn’t provide me with this, nor does it seem to provide me with enough information to calculate this statistic manually. How would I acquire this statistic given the information I have available to me? (I have included pictures of this below).