Tutorial Video. Step by step below;

1

First Step

Download your desired Datapack from the web. (We prefer using Planet Minecraft)
2

Second Step

Click on the Download Datapack button.
3

Third Step

Login to your Wepwawet Control Panel
4

Fourth Step

Select your Server
5

Fifth Step

Make sure to Turn OFF the Server
6

Sixth Step

Under the General Section, Click the Files tab and select your current world folder.
7

Seventh Step

Click on the datapacks folder.
8

Eighth Step

Upload the downloaded datapack file. (as a .zip file)
9

Nineth Step

Head over to the Console tab and Start the Server.
There you go! You now know how to install a datapack onto your Server