Look, there's no best SEO Schema FAQ Generator. All these tools - if properly set up - in the end do the same job. So feel free to use it. If it helps, give it a share.
Usually, a Frequently Asked Question (FAQ) page contains a list of questions and answers on a particular topic.
FAQ schema markups are a standardized format for providing information in Microdata or JSON-LD.
Pages that are properly marked with FAQ structured data can be eligible to have a rich result on Google search.
Implementing FAQ schema can potentially improve your impression count from the search results page and help to provide users better experience. Note that since you're serving the user all answers right on Google, it might redure CTR and users coming on your website.
The code should placed within the HTML of a page, doesn't matter if it's high or low on the HTML code.