I was successful thanks to previous comments, these were the steps and files:
-Extract files in a folder
-Go inside the "adb-fastboot" folder, in the address bar write "cmd" and hit enter to open a terminal
-Run
Code:
adb shell getprop ro.serialno
-Copy and Install SpreadTrumTools.apk in your tablet
-Open the app, allow permissions and input the serial you just obtained
View attachment 5443947
-Tap Generate
-Copy the file "signature.bin" inside the adb-fastboot folder in your computer
-In the terminal run
-Wait for the tablet to boot into fastboot, if for any reason boots into fastbootd, navigate to reboot to fastboot
-In the terminal run
Code:
fastboot oem get_identifier_token
-Run
Code:
fastboot flashing unlock_bootloader signature.bin
View attachment 5443949
-Follow instructions in your tablet (press volume down)
-If everything is successful you should see something like this
View attachment 5443951
Hope it works for you