JS function for Node to mirror the exact png source code in HEX to a .txt file

I need a function in JavaScript for Node.js backend which is able to exactly convert a png to a hex code without manipulating, changing, reordering, etc the source code of the png and then write it to a txt file without spaces between hex values. You can use Notepad++ for example to convert a png to hex code and compare it with the result of your JS function.
Please provide an efficient and state-of-the-art JS code. Do not use bad rated (by Snyk), old, mini or not well maintained Node packages.

See two example png attached, one even converted to hex code (react.txt)