If you want to add any DSP or SPP channel as part of automation journey it can be done easily with Mapp Engage and Mapp Acquire.
Onsite-pixel on customer page (preferable on all pages)
Active integration between Mapp Acquire<> Mapp Engage (email and whiteboard)
Active integration with one or more DSP platform like Appnexus, Adform, Google Adwords
An audience that is able to send users to Mapp Engage after they register (or fill any other form) or Contact Registration event set up
An audience integrated with DSP
Create Audience (s) integrated with DSP, SSP platforms - if you want to direct to it users only from Engage (and no other web-users) you need to create conditions not possible to be passed example: URL doesn't contain: ‘your-domain’
Create a matching point for a user like an Audience integrated with Mapp Engage or Contact Registration Event. If one of the Whiteboard journey (or entry one) you would like to use DMP audience - create audience integrated with Mapp Whiteboard.
Create an Event-based Whiteboard and use block 'Add to DMP Audience” with destinated DSP channel - users will be added and sent to DSP directly (without passing audience criteria).