I’m developing a system for my company where I need to show if some services are online and I cant see on Auth0 any route that I can just call and give me this. I want something that I dont need to pay or spend a lot of money because of that.
Each time you need to check whether your API is working, you will have to request a token. This will only be expensive if you are making too many requests to get an M2M access token.
Keep in mind that you could cache the access token for the duration of its lifetime, to avoid repeated M2M auth calls. Additionally, you can check your monthly M2M auth usage on support.auth0.com.