all links are deleted

fastboot is an option is used to forcefully stop system Application....so change it to normal

@@technoscienceinfosec That's not true, fastboot is technically disabled on OPPO phones by default.

@@RaymondHsu now how to flash any file

You mean SD card. Some time Yes and also no. The reason is the mounting system is protected, so if you try to load a file using ADB TWRP then the process failed, as the Internal memory not mounted.

Yes, it is possible to install LineageOS (a custom Android ROM) on your Oppo A9 2020, but please be aware that the process of rooting and installing custom ROMs can be complex and carries some risks. Here's a general outline of the steps you might need to follow: 1. Unlock Bootloader: Most devices require an unlocked bootloader to install custom ROMs. Check if your Oppo A9 2020 can have its bootloader unlocked, as some manufacturers restrict this. 2. Rooting: Rooting allows you to gain superuser access to the Android system. This step is often required to install custom recovery and custom ROMs. Research the specific rooting method for your device model and Android version. Remember that rooting can void your warranty and might cause security risks if not done properly. 3. Install Custom Recovery: To install LineageOS, you'll need a custom recovery like TWRP (Team Win Recovery Project). This allows you to flash custom ROMs and create backups. Follow instructions for installing TWRP for your specific device. 4. Backup: Before proceeding, back up all your important data, as installing a custom ROM will erase your existing data. 5. Download LineageOS: Visit the official LineageOS website to download the appropriate ROM for your device. 6. Flash LineageOS: Boot into recovery mode (usually by pressing a combination of hardware buttons) and use TWRP to flash the downloaded LineageOS ZIP file. 7. Gapps: If you want to use Google services, you'll need to install Google Apps (Gapps) separately. Download the appropriate Gapps package for your LineageOS version. 8. Wipe Data: Perform a factory reset or wipe data/cache from the recovery menu. 9. Flash Gapps: After wiping, flash the Gapps package. 10. Reboot: Reboot your device, and it should boot into LineageOS. It's important to note that the process can vary based on device models, Android versions, and other factors. Before proceeding, make sure to thoroughly research the process, understand the risks, and follow trusted guides specific to your device model and Android version. If you're not comfortable with the process, it might be best to seek assistance from experienced users or consider other options.

Same mujhe bhi krna h x688b ka

I know you already did

0:26

i have no such device

Watch the Android rooting video to root any Samsung device

Link: download.highonandroid.com/download/Drivers/UniversalAdbDriverSetup.msi?token=594999693

Link: download.highonandroid.com/download/Drivers/UniversalAdbDriverSetup.msi?token=594999693

Did you face any problem. I am sorry.

@@technoscienceinfosec can you tell me what to do, it says no OS installed

Download required software before rooting