You state in https://confluence.atlassian.com/bitbucket/publishing-a-website-on-bitbucket-cloud-221449776.html
Publishing a static website on Bitbucket Cloud requires you to combine your account's name with the <a href="http://bitbucket.io" rel="nofollow noopener noreferrer">bitbucket.io</a> domain suffix. So, your account's name must be acceptable to your DNS service. Upper case characters and special characters are typically not acceptable. For example, if your account's name is happy_cat, you would need to create a new account with a username of happycat to use this feature because underscores are not allowed in DNS hostnames. Your repository name would be <a href="http://happycat.bitbucket.io" rel="nofollow noopener noreferrer">happycat.bitbucket.io</a> and the published static website is reached by this URL: <span class="nolink">https://<code>happycat.bitbucket.io
Great. I have an underscore in my username, which I've had with Bitbucket for almost eight years. Now I have to get another account? Oh, and I guess I need to sign up with another email address because Bitbucket won't let me create another account with the same email address.
Could you please just map underscores into hyphens, which are a legal URL domain name?