ECDSA prime256v1 CSR file signing

Hello guys, I would be very pleasured for a small advice. We're changing a SSL certificate for our production server. Untill now we were using RSA as CSR generation alorithm. However Symantec now offers signing with ECC with RSA root so we would like to swtich to this variant. My question is: In this case, do I have to generate CSR with key type ECDSA and curve name prime256v1 to be able to send for signing with ECC with RSA root to Symantec? We use BIG-IP model 2200 , Version 11.5.1. Many thanks for your response. Ivan