You can use any of the free Samsung firmware update tools to download the Samsung SM-A710M stock ROM to your desktop. And once you have the firmware on your desktop, use the Odin flashing tool to install it. The Samsung firmware update tools are free and developed by developers on XDA Developers and GitHub. Thousands of people use them every day and it’s not difficult to see from their GitHub and XDA pages that they’re reliable tools. The Samsung firmware update tools can download the firmware files directly from Samsung’s servers, so there is no middleman you need to rely on. This makes them a better option than downloading firmware files from independent sites.