1 - Download BisKeysDumper (Google it for link), decompress and put the bin file in the root of your SD card
2 - Boot to your SX OS menu, select Options/load external payload, and select biskeysdump.bin
3 - your keys should show up on the screen together with a QR Code
4 - Use your phone with your favorite app to read QR Codes (or download one from playstore/AppStore) and scan the code
5 - Backup the text in a doc file and keep it in a safe location