Old Firmware
Samsung may not serve the firmware you request. Early in 2023, Samsung made it so it's only possible to download the latest firmware in most cases, no matter which you request.

If you know a workaround, please follow up on this issue.

IMEI/Serial Number Requirement
Samsung now requires a matching IMEI or serial number be sent with firmware requests. If you're downloading firmware for a device on-hand, enter the IMEI or serial from that device.

Otherwise, you can likely find an IM