Yes, immediately. The Oppo F1s is out of warranty by now (released 2016), so this is irrelevant for most users.
: This version was never released by Oppo for the F1s. Any "7.1.2" downloads found online are third-party custom ROMs (like LineageOS) or potentially malicious files. Oppo F1s Firmware Download 7-1-2
Before downloading any firmware, verify your exact model number. The Oppo F1s comes in two primary variants: Yes, immediately