I created an Android Project. Now I want to add Firebase into my android project. I register my application on firebase console. Now When I try to add my sha-1 key in to project it gives me following error.
I search on google and stackoverflow but didn't receive any proper answer. According to some answers this error occurs when I insert same sha-1 key in to another project of firebase. Let me tell you that this is my only project in firebase console. I do not have any other project in this firebase account.
So what could be the problem and how can I add this sha-1 in my firebase project ?
Finally I Have solved issue my self,
Firebase internally stores each package name with associated SHA-1 Key. So When we are using same package name & SHA-1 in firebase, it will not allow to user it and produce the same error mentioned in the question. To solve we need to either change package name or need to user another keystore's SHA-1 key.
You may have/had an app in any firebase project with same package name/bundle id and SHA1 fingerprint. I had tried to delete the certain app from the project that I created earlier. But it won't help me even after 24 hours of app delete operation. (I believe that it will take some time for update the app details in the firebase projects config)
So I had tried to delete the entire firebase project that I created earlier and tried to create the new app with same details in the new firebase project.
It Works... (In my case I was aware of two firebase projects that have the apps with same details)
To get Debug certificate run this command C:\Program Files\Java\jdk1.8.0_131\bin key tool comes with the Java SDK.
keytool -list -v -keystore C:\Users\DELL\.android\debug.keystore -alias androiddebugkey -storepass android -keypass android
Delete and Restore Your Firebase Project (Worked 2019.07.10)
来源：https://stackoverflow.com/questions/48474872/your-operation-was-forbidden-issue-in-firebase-console