hi, does anyone know how to include resistor models? I do .lib "..." ff or ss or tt and the models are not picked. However HH works, but the transistors are TT, which is not what I am intending.

What are you intending to include? The set of corners is intentionally limited, so that all back-end corners use typical front-end parameters, and all front-end corners use typical back-end parameters. If you want something unavailable like

hhss

, I'd recommend creating your own local version of

sky130.lib.spice

and include the specific corner models you want by "mixing and matching" from the ones that are in the file.