Generating a bespoke pdf for each user from web app data

--Background-- I'm very much at the beginning stage of the web app and would like some general 'have you considered going in this direction' type advice.

I'm building a customisable instruction manual to solve a fault in a washing machine. Not keen to overcomplicate this question i've simplified the situation in my question.

As an example the web app might ask the following questions - would you like a picture of a yellow square jn your manual? (Yes/no/maybe) - would you like a picture of a blue dog in your manual? (Yes/no/maybe) - would you like a red umbrella in the manual (yes/no/maybe)

I need to build a web app which can build a pdf based on their responses. For example: If they answered 'yes' 'no' 'yes' then they would need a pdf with a yellow square and a red umbrella underneath it that they could download from my website

--What I need help with-- Essentially I can build a web app that stores all their answers to the questions in a database, but I have no idea how to convert that information into a pdf that they can download from the site. A complicating factor would be some of the images to be built into the pdf are different physical sizes and it must fit onto A4 pages that can be printed easily.

(people have previously mentioned jasper reports, itext or even building it in LateX, what would you recommend and how might I go about doing that?)