do I need an extra account for an alias?

I use the free version which is limited to 2 accounts. In one of them I use also an alias, which means I get mails sent to the alias and to the full name through the same account.
But so far I could not find a way to SEND from the alias. Can I add that to the account or do I need to create an extra account for the alias to be shown as the sender?
Thanks for your help and cheers from Vienna,

Hi Gertrud,
if you’re using aliases and want to sent from the alias, navigate to Tools > Accounts > Your accounts > Aliases, and add your second email address to the list of aliases, after you do so, you should be able to select the email address as the “From” address in the dropdown of available accounts when composing a new message.

If a message is sent to your alias and you want to reply to this address, the alias should also be automatically assigned as the from address.

Hope this helps,