How do I download a driver to connect Oppo A33f to PC?
You can download the drivers from from the Android MTK website. I've linked the URL below to make it easier to reach the downloads. The driver for this type of phone should be located among the first ones. Click the green Download button and then a new page will load where you can download other drivers for the operation you want. However, for this phone, there is only the ADB one.