openssl_pkey_export_to_file

Supported Versions: PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8

Gets an exportable representation of a key into a file

        openssl_pkey_export_to_file(    OpenSSLAsymmetricKey|OpenSSLCertificate|array|string $key,    string $output_filename,    ?string $passphrase = null,    ?array $options = null): bool