I have created another account by mistake. How do I request the accounts to be merged?
Community moderators cannot merge accounts anymore. You need to ask to Stack Exchange stuff to do it.
Click on contact us, the link you find on the footer.
On the next form, for What can we help you for? select I need to merge user profiles.
Fill the other fields, and click on submit.
Keep in mind that, to ask to merge two accounts, you need to be logged-in with one of them, and you need to click on contact us on the site where you have both the accounts.