Just opened an account

Been doing a lot of research and couldn’t figure out what the best HYSA account to use , but Wealthfront was the most recommended in most of the threads. I do have a question though. I realized I didn’t use the link someone put on one of their posts, is it too late to add it to get an extra .5 APY? I know they gave me a referral code to give out but I was hoping to use someone else’s.