There are a few different ways that you can format your Oppo phone. You can do it through the settings menu, or you can use a third-party app.
If you want to format your phone through the settings menu, you can go to the "System" section and then tap on "Factory Reset." From there, you can choose to reset your phone.
If you want to use a third-party app, there are a few different options that you can choose from. One option is to use the Android Debug Bridge (ADB) tool. This tool is typically used for developers, but it can also be used to format your phone.
Another option is to use a tool called "fastboot." This tool is typically used to flash a new firmware onto your phone, but it can also be used to format your phone.
You can also use a tool called "Dialer ##7780##" to format your phone. This tool is typically used to reset your phone to its factory settings.
These are just a few of the different ways that you can format your Oppo phone. Choose the method that you feel most comfortable with.