I'm trying to use the simbiology app to fit data with a simbiology model. The problem is that between the data groups there is a independent variable (AHL) that changes between them (image 1). When the data was imported I defined the AHL row as a covariate (which I think is right) as seen in the image 1. The problem is that when I go to the data fit program in the simbiology app, at the part when all the other variables are defined (image 2), there is no option to define this AHL row as a covariate that needs to be linked to a parameter of the simbiology model (this, as shown in the image can be done for the group, independent and dependent type of variables). Is there a way I can do to define the AHL parameter so that it changes between data groups in fit data program of the simbiology app?