It can be filled temporarily, but it is not recommended to use for a long time.
Apple 8 series is more than support PD fast charge protocol, millet PD charging head is also compatible with a variety of protocols, in its official publicity is also said to Samsung, Apple and other products for charging.
However, Apple's official recommendation, including my recommendation, is to buy with MFi certification (MFi certification is Apple's official certification of its authorized accessories products).
The same brand for the same brand is better.
Xiaomi fast charger can not charge iPhone mobile phones. If used, it will damage the iPhone. The withstand voltage value of the iPhone is about 5 volts, and the use of fast charging will puncture the electronic components inside the iPhone, causing damage to the iPhone. And millet ordinary charger can charge Apple mobile phones.