Hello,
The NE20E is a Layer 3 device and works at the network layer. It cannot identify the data from Layer 4 to Layer 7. Therefore, if you want to process the date of the application layer, you can use only the Layer 4 to Layer 7 devices similar to the USG.
please refer to:
https://support.huawei.com/hedex/hdx.do?docid=EDOC1100068394&id=sec_admin_bwm_0002&lang=en
I hope it helps.