You can play 100XSMP by adding the server in the Minecraft launcher.
On Minecraft Bedrock Edition, open the Minecraft launcher or Minecraft app. Go to the “Servers” tab and press “Add Server.” Enter the 100XSMP IP Address file-rain.craft.ply.ggin the “Server Address” and the 100XSMP port 19132 in the “Port.” Then press “Save” and start playing.