WebAssembly-based web application that is capable of download Samsung OTA firmware files directly from the browser via Samsung's OMA-DM FUMO service.
Demo: https://fumo.timschneeberger.me/
Note: This app is unfinished. Samsung may require a real IMEI registered to a Samsung phone, otherwise the OMA-DM device registration can fail.
Firmware for the Samsung S8 could be retrieved with no issues using randomized device ids and IMEIs, the S20 for example, does have problems though. You can play around with the downloader by selecting the Advanced mode tab.
This project is licensed under GPLv3.0.