You have to use the SHA-1 key generated by Google. Following steps would fix it.
1). Go to Google console => your project => Setup => App Integrity => App signing key certificate.
2). Copy SHA-1 certificate from there and as it’s in hexadecimal and since Facebook needs it in base64 so use the command shown in step 3
3).echo SHA-1 key from step-2 (Hexadecimal) | xxd -r -p | openssl base64
This command won’t work in command prompt use bash on windows or git cli.
4). Paste the base64 key in Facebook console => Settings => basic => key hashes