Download official Samsung phone firmware

Does Samsung provides official firmware (old phones included)? I have found only user manuals on the web page. I'm looking for equivalent of Google's https://developers.google.com/android/images which allows full reinstallation with Linux (I know that fastboot was replaced by Odin, thus I'll have to use https://github.com/Benjamin-Dobell/Heimdall) . I've found these sites, but these aren't official, right? * https://www.sammobile.com/firmwares/ * https://www.sammobile.com/ * https://updato.com/ The reason I want is that I'd like to test postmarketOS (https://wiki.postmarketos.org/wiki/Samsung_Galaxy_J5_2016_(samsung-j5x)) and then I'd like to revert back. UPDATE: the question is not "which tool should I use" (although that is useful to know), but "what is the official URL for downloading images. Is there any for updating by user clicking on the web page? (there might be just REST/other API for devices). Looking at * SamloaderKotlin : * https://www.odinrom.com/samsung/ (https://github.com/zacharee/SamloaderKotlin/blob/9fee3940855d1a4cd565ae2f6896cdb0ee826782/common/src/commonMain/kotlin/tk/zwander/common/util/Firmware.kt#L27) * https://fota-cloud-dn.ospserver.net:443/firmware/ (https://github.com/zacharee/SamloaderKotlin/blob/9fee3940855d1a4cd565ae2f6896cdb0ee826782/common/src/commonMain/kotlin/tk/zwander/common/util/Firmware.kt#L45) * https://neofussvr.sslcs.cdngc.net (https://github.com/zacharee/SamloaderKotlin/blob/9fee3940855d1a4cd565ae2f6896cdb0ee826782/common/src/commonMain/kotlin/tk/zwander/common/tools/FusClient.kt#L76-L89) , document: "Make a request to Samsung, automatically inserting authorization data." - is this really Samsung official? * samloader (already deprecated): * https://fota-cloud-dn.ospserver.net/firmware/ (https://github.com/samloader/samloader/blob/95d2ac8fb9027b7908d201e4ce807a5b338f923a/samloader/versionfetch.py#L20) * http://cloud-neofussvr.sslcs.cdngc.net (https://github.com/samloader/samloader/blob/95d2ac8fb9027b7908d201e4ce807a5b338f923a/samloader/fusclient.py#L40) * https://neofussvr.sslcs.cdngc.net/ (https://github.com/samloader/samloader/blob/95d2ac8fb9027b7908d201e4ce807a5b338f923a/samloader/fusclient.py#L19)