For your Adobe Commerce on cloud infrastructure project, you may change the New Relic account owner on the New Relic UI page. For detailed steps, see Change the account Owner in New Relic documentation.
If the user (that you want to assign the owner role to) is not listed on your account yet, you will need to add the user to the account. See Add and update users in New Relic documentation, in particular the Add a new user section.
If someone needs to be added as a user, but no existing Owner or Admin on the account can help them, any Adobe Commerce user who has access to the New Relic’s Adobe Commerce Partnership Owner Account is able to view all Customer accounts and add users on the Customer’s behalf.