To add parameters to the reaction, go back to the properties tab. Go to the tree list "Possible Referenced Objects" on the right side of the window. The selected reaction "Re" should appear at the top of the tree. Extend the tree view of "Re". The parameters k1, k2 and Km should be listed below "Re". To add the parameters to the list of referenced objects, drag & drop each parameter into the list to the left, where "Educt", "Product" and "Drug" are already listed.