如何创建像CTRL + F这样的函数来获取PDF和HTML的字符串

I want to ask how to create function like CTRL+F for my search bar on my HTML. for simple example here I have a code at my body html like this :

    <form class="example">
    <input type="text" placeholder="Search.." name="search">
    </form>

I want to find some text with that search bar function (like CTRL+F function), I have a PDF file on my HTML, my goal is i can find some text on that PDF, where the pdf is raised in my html. i want find some text on that PDF with my find function. someone can guide me ? I'm so tired of trying every way I find on google but always fail... oh yeah, usually I'm trying with javascript code.

Please help me, thanks in advance.