Thank you Sam !
I'm using Firebase Cloud Functions, Storage , Hosting and Firestore at the moment. And as I'm trying to make API calls from Cloud functions, I realised it could only be done with a paid plan. And what I am afraid is if I switch to Flame or Blaze during my testing, I'll get a huge bill for a programatic mistake.
Best would be to be able to make API calls from the free tier if possible. If not, ensuring any services running above the free tier quota will stop and not be charged for additional usage.
I understand it's not really on Firebase's best interest to do so, but would make it more confident for a dev test period. I clearly can't offer 1K of service at that stage...
Thanks !