How do I use attributes/attribute modifiers within java code to change a Minecraft players maximum health (not absorption effect or health boost)

I'm creating an item that when equipped I want it to increase the player's max health and I also want it to be stackable with multiple items so it can't just be absorption or health boost. A lot of people have told me I need to use entity attributes but after hours of trying to figure out how to use them, I am at a complete loss. I'm on version 1.18.2 using forge.