You can play MastroiSMP 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 MastroiSMP IP Address mastroiSMP.vgh.huin the “Server Address” and the MastroiSMP port 19132 in the “Port.” Then press “Save” and start playing.