Why can't i get property nbt.value.value from a item object?

[Daniel-Glz]

I was trying to get the type of a splash potion through nbt property of a item, but i can't get it. When i try to get it returns me undefined, Why is happening this?

My code:

const mineflayer = require('mineflayer');

const options = {
    host:"localhost",
    username:"ImABot",
}

const bot = mineflayer.createBot(options);


bot.on('chat', () => {
    let inventoryArr = bot.inventory;
    let potion = inventoryArr.findInventoryItem(438).nbt.value;
    console.log(`item.nbt.value: `);
    console.log(potion);
    console.log(`\n\nitem.nbt.value.value:\n ${potion.value}`);
});

When i run my code, potion returns me this object { Potion: { type: 'string', value: 'minecraft:strong_healing' } }
and i try to get its value property but it returns me undefined

[u9g]

.Potion.value not just .value