Firebase deployでエラー

firebase deployコマンドすると、下記のエラーがでる。

✔  functions: Finished running predeploy script.
i  firestore: reading indexes from firestore.indexes.json...
i  cloud.firestore: checking firestore.rules for compilation errors...
✔  cloud.firestore: rules file firestore.rules compiled successfully
i  functions: ensuring required API cloudfunctions.googleapis.com is enabled...
i  functions: ensuring required API cloudbuild.googleapis.com is enabled...
⚠  functions: missing required API cloudbuild.googleapis.com. Enabling now...
✔  functions: required API cloudfunctions.googleapis.com is enabled

Error: Cloud Functions deployment requires the pay-as-you-go (Blaze) billing plan. To upgrade your project, visit the following URL:

https://console.firebase.google.com/project/chatbot-demo-bfa6b/usage/details

For additional information about this requirement, see Firebase FAQs:

https://firebase.google.com/support/faq#functions-runtime

解決策

下記のstackoverflowで解決。

package.jsonの、nodeを"8"にダウングレードしたらいけた(今は)

"engines": {
"node": "8"
},

Cloud Functions deployment requires the pay-as-you-go (Blaze) billing plan [duplicate]