not able to create hash key for android app: I get the error "keystore JKS utilize a proprietary format"

I want to create hash key for my android app.

According to all the web this is the command:

keytool -exportcert -alias <RELEASE_KEY_ALIAS> -keystore <RELEASE_KEY_PATH> | PATH_TO_OPENSSL_LIBRARY\bin\openssl sha1 -binary | PATH_TO_OPENSSL_LIBRARY\bin\openssl base64

When I execute this command on windows I get this message:

The JKS keystore uses a proprietary format. We recommend migrating to PKCS12, an industry standard format, using the "keytool -importkeystore -srckeystore command ...

I do not know what I should do right now.