Generally, this option is only on Samsung devices where users can easily flash that they want in internal flash memory via USB cable. In between this mode, if something goes wrong then it stuck at Download more (Odin mode).
So to get out of this error, some of the steps you need to follow. They are:
Force restart your device by pressing Volume down + power button to restart the device. If not then press and hold Power + Home + Volume Up + Volume Down to reboot the device.
Remove the battery is possible. As nowadays, the devices are coming with non-removable battery so it can be a problematic but if possible the once remove the battery.
You can also download Odin flash tool with right firmware and can solve the issue. If not then you can use third party tool like Android Data Extraction, which is one of the best tool to fix Samsung stuck in Odin mode. It repairs every errors like Samsung stuck in Odin mode, repair broken phone, extract data from damaged phones etc.