If you want to obtain a SSL certificate for your Synology diskstation, we recommend to NOT use our Online CSR/KEY generator but instead follow the instructions from the Synology knowledge base: https://www.synology.com/en-global/knowledgebase/DSM/tutorial/Network/How_to_enable_HTTPS_and_create_a_certificate_signing_request_on_your_Synology_NAS#t4.2
After you have created the .CSR file (see also: What is a CSR?) you can place the contents of your CSR at the certificate in your "My InterSSL" account to request your SSL certificate from the Certificate Authority (CA). After successfully approving the domain validation, you will receive the .CRT files needed for finishing the installation in Synology.