You can easily find Estatik Search in Widgets area of any WordPress website. If you're using Elementor, we will explain how you can setup Estatik Widget via this builder.
Open the page with Elementor and open Elements Menu. Find Estatik elements there:
Please note that a different search layout has a different fields settings. You can see below that Simple and Main layouts has extra fields selection for collapsed fields while Advanced Search has one set of fields: