How to Get SHA-1 key in React Native cli?

There is debug.keystore available by default in android => app folder so we can use it to generate SHA1 key.

The command is as follows

keytool -exportcert -keystore ./android/app/debug.keystore -list -v

It will ask for password so just press Enter.

As far as I understand you, it's about Android.
You need input certificate fingerprint, what you use for sign *.apk file.
For generate SHA-1 fingerprint, open a terminal window and enter the following:

keytool -list -v -keystore PATH_TO_YOUR_KEYSTORE.keystore -alias YOUR_ALIAS_NAME -storepass YOUR_STORE_PASS -keypass YOUR_KEY_PASS

This should look something like this:

BB:0D:AC:74:D3:21:E1:43:67:71:9B:62:91:AF:A1:66:6E:44:5D:75

You can find more information here
If you don't have a certificate yet, I recommend you create it.
How to create a certificate you can read here.

Get SHA1 Key

Simple run below command :

keytool -list -v -keystore ./android/App/debug.keystore -alias androiddebugkey -storepass android -keypass android

1. Windows:
   – Open a terminal window

   – Change the directory to the JDK bin directory. The path of the JDK depends upon the operating system you are using

   cd C:\Program Files\Java\jdk1.8.0_121\bin

   – Now we have to run the following command using the keytool.exe file in JDK/bin

   keytool -list -v -keystore "%USERPROFILE%\.android\debug.keystore" -alias androiddebugkey -storepass android -keypass android

   

2. Ubuntu/Mac

   – Open a terminal window

   – Now run the following command

   keytool -list -v -keystore ~/.android/debug.keystore -alias androiddebugkey -storepass android -keypass android

   

For more details click Here

3. From React-native Project:
   – Run this command in React-Native App directory

   cd android && ./gradlew signingReport

   – copy the SHA1 from the debug key (This generates two variant keys. You can copy the 'SHA1' that belongs to the debugAndroidTest variant key option.)