If you've imported send as addresses from Gmail, you can send your sequence from any of your email aliases.
How to use aliases with Sequences
Using an alias works best with single-stage sequences or with sequences where all stages should be sent regardless of whether the recipient opens or replies.
If you'd like to use a different email address to send a sequence that requires response tracking, we recommend using Delegated Sending.
To send a sequence using an alias, select a send as address in the From field within any (or all) stages: