Don't worry, this is a fairly common experience, e.g. if you buy separate individual tickets for you and a friend. In this case, you will receive a separate 'Profile activation' email for each ticket that you purchased. These will be addressed to the name on the ticket, and will have unique profile activation links for each person. You should activate your own profile, and then send your friend their profile activation link (found in the email addressed to them).
Once they've activated their profile, they will be able to navigate to https://www.raceforimpact.com/account and update the email address attached to their profile.
Doubles and relay teams: my email shows on my partner's ticket
If you bought a doubles or relay charity ticket for your team, your email appears on every seat of the HYROX ticket because you were the buyer. That does not mean your partner's page is under your email. Race for Impact uses the athlete email you entered for each seat when you personalised the tickets, so your partner's page is linked to their own address and all their emails go there. Your partner should go to raceforimpact.com/login, enter their own email address (not yours) and click the link we send them. If they cannot find it, ask them to check spam for emails from Race for Impact, or message us here with your team page link and we will send them a direct link.