A 3.5mm headphone jack is really important for a smartphone. Without this jack, we would not be able to use ordinary headphones on our phones. This important feature is not seen in many phones now. If you use Oppo Reno7 5G (China), you will also fall into that trouble because there is no 3.5mm headphone jack on the phone.
Your Oppo Reno7 5G (China) doesn’t have a 3.5mm headphone jack. So you can’t use this type of headphones on the phone. But there is given another alternative to it. So you don’t have to worry about that.