Portfoliobox has a dedicated area for SEO, it is called SEO section. This section can be found under Cogwheel > Settings > SEO.
In this section, you can add different information about your website. For instance, the site meta description, your website type and details on your business. The information here are used as the structured data of your website. Structured data is a markup that gives additional details on your website, it helps search engines better understand your content. When the search engines understand what your website is about, they would be able to display your website in the relevant search results. In Portfoliobox, we are using Schema.org markup.
Please note that even though you have completed the whole SEO section, it does not mean that the search engines would use and display all the information provided. However, the rule of thumb is, the more information you provide to the search engines, the easier it would be for them to understand the context of your website.