I am a minecraft commander.

/execute at @s[nbt={SelectedItem:{id:"minecraft:netherite_pickaxe",Count:1b,tag:{Enchantments:[{lvl:32769,id:"minecraft:efficiency"}]}}}] run tellraw @s {"text":"This is a test message. This means that I written it correctly","color":"#00FF00"}

For the upper command work: /give @s minecraft:netherite_sword{Enchantments:[{lvl:32769,id:"minecraft:efficiency"}]}

Hold the netherite sword in the hand and then run the first command.

1.16+