In order to setup your domain on the Gmail delivery dashboard offered by Google, you will need to create another TXT record in your DNS. The TXT value for this record will be shared by Maropost to you once you tell us what your From domain is. The value is unique per domain and we cannot share that value in this document.
Let your Customer Success Manager know what From domain you intend to use for your email campaigns. Maropost will provide you with the TXT value that you need to add in your DNS server where your domain is hosted.