Here is the full solution for CraftConnections Day 23. Each group is shown with its difficulty colour and a redundant shape, so it stays readable if you are colour blind.
Classic — Day 23
● Shovels Golden Shovel · Diamond Shovel · Copper Shovel · Iron Shovel
▲ Chestplates Iron Chestplate · Diamond Chestplate · Netherite Chestplate · Golden Chestplate