Firebase hosting with only ONE A record : <p>I have my client's domain registered via 1and1.com </p>

<p>To connect the domain to the Firebase hosting, Firebase asks me to add <em>TWO</em> A records with 2 IPs. In 1and1 we can only add <em>ONE</em> A record. Yesterday Firebase sent me this message by mail </p>

<blockquote>
  <p>Please re-verify ownership of www.*******.com on
  *******-website. The previous verification for this domain has
  been invalidated. You have 1 day to re-verify ownership of
  www.*******.com before it is removed from Firebase Hosting,
  which will stop all content from being served from the domain. Please
  visit the Firebase Hosting Panel to start the re-verification process.</p>
</blockquote>

<p>Today the website was disconnected.</p>

<p>I reconnected the domain to the Firebase hosting through the Firebase control panel and got the website up again. But the Firebase control panel says it still needs setup</p>

<p>I am sure it will disconnect it again soon. How to solve that? (I already called 1and1 and they told me no way I would be able to add another A record.) 
<a href="https://i.stack.imgur.com/It6e3.png" rel="noreferrer"><img src="https://i.stack.imgur.com/It6e3.png" alt="enter image description here"></a></p>
