Pair your SSL & Private Keys
Whether you are renewing your SSL certificate or installing a new one, before continuing with the installation process, you must verify CSR and Private Key. Luckily this is pretty easy for you. Using the OpenSSL commands below, you can check which CSR belongs to which certificate and similarly which private key matches which certificate.
openssl pkey -in privateKey.key -pubout -outform pem | sha256sum
openssl x509 -in certificate.crt -pubkey -noout -outform pem | sha256sum
openssl req -in CSR.csr -pubkey -noout -outform pem | sha256sum