Merge's wallet is made up of two halves. One is the public, shareable part called the public key. The other is the private part that is required for spending the stored MERGE in that wallet. If you want to receive MERGE into your wallet, you should provide one of your public addresses. Think of the public part of Merge's wallet as your email address and the private part as the password to that email address: you can share the email address freely, but not the password.