After testing multiple Tecno Spark 6 Go units (KE7), here is the recommendation:
Simply entering Fastboot mode does not delete any personal data. However, running commands like fastboot oem unlock WILL factory reset the device. how to open fastboot mode on tecno spark 6 go
When you're in Fastboot mode, you'll see the Fastboot logo on your screen. You can also verify by checking the device manager on your computer: After testing multiple Tecno Spark 6 Go units