In android studio when i release a build through
menu -> Build -> generate signed APK
Apk is prepared. now i have generate
keytool -exportcert -alias MeasurePal -keystore E:\Key\MeasurePal.jks | C:\OPENSSL\bin\openssl.exe sha1 -binary | C:\OPENSSL\bin\openssl.exe base64
got a key: iHI806h/qu6wABNnAzlyRiuPhf4=
but it not grand access from Facebook.