Configuring FreshClick App on BigCommerce e-Shop

Our company sells vibration sensors. We currently have 3 online shops, which are managed thank to BigCommerce. On one of these e-shops (€ shop) we would like to propose an advanced search skill, that's to say that customers can filter products according to different criteria. Such as, in our case, sensitivity of the sensor, weight, connector direction, frequency, temperature... All these criteria have to be custom ones, because it's very specific to our business. To do this, we have installed the FreshClick App, an add-on in BigCommerce, because we have a standard plan and the filtering feature insn't included. We have a 10 days free-trial, and it remains 6 days. The problem is : we don't achieve to put an options set as filter. All the informations about the work to do are in the attached file.