Under normal circumstances you should be able to sign in to your eBay account with only a username and password. If you have a social media account linked to your eBay account, you may be able to sign in using your social media account.
If you use 2 factor authentication, are subject to verification (such as users in the UK are), or you need to reset your password, then you may need access to the email address or phone number associated with your eBay account. You may also be able to verify using the eBay app in some cases.
