Need an expert in Gravity Forms

I need an expert in gravity forms to design a form according to the design scheme of the website.
To qualify for this project, you need to answer the following question:-

This form was built in gravity forms, https://fixx.co.uk/build-a-boiler/
Which plugins were used to create this type of interactive form, this website was made by us, so we know what we used before, I want you to tell us what you will use.