How can I check if the item in a slot is a specific potion in MCreator 2025.2?

Hey everyone,
I’m working on my mod in MCreator 2025.2 (NeoForge 1.21.1).
Right now, I’m trying to check if the item inside a specific slot (for example slot 1 of a custom GUI) is a specific potion, like a Potion of Healing.

Here’s what I tried so far in a procedure:

Question:
👉 What’s the correct way in MCreator to check if an item in a slot is a specific potion (e.g. minecraft:healing)?
Do I need to use tags, NBT, or some built-in function?

Thanks in advance for any help! 🙏