Is peppermint oil safe or unsafe to use in a diffuser if you have a dog?

I’ve been trying to research which essential oils are safe to use around dogs, and peppermint oil has completely stumped me. I’m seeing totally different answers. Some articles say it can cause extreme harm and even kill a dog, while others say it’s harmless and is even used in dog-approved products. I’m not sure which source to trust anymore, everyone and everything is saying completely different things