Warning openssl_sign supplied key param cannot be coerced into a private key

This warning message indicates that the key parameter supplied to the openssl_sign() function is not a valid private key.

To fix this issue, you need to ensure that you are using a valid private key that is compatible with the openssl_sign() function. Make sure that the key is properly formatted and that it is not corrupted or invalid.

If you are unsure about the format or validity of your private key, you can try regenerating it or consulting with a security expert who can help you troubleshoot the issue further.