What number is +8696088?

You don't have to answer such a call in China. It's all virtual numbers.

You can do an experiment. Dial a number for your mobile phone with a customized fixed telephone, and there will be no+sign in front.

Therefore, it is bold to guess that the+sign appears because the other party dials in outside the domestic mobile network, that is, the virtual phone number on foreign telephones or the Internet. So it's not worth believing. There's a high probability that it's a scam.