The latest plan is that they would apply for grants to get themselves started, build a track record and deliver first items that show their effectiveness.
Then they would use this as a basis to apply for a separate budget through PTIP at a later stage.
This is the model they chose based on the feedback on their first proposal that a large blank-check budget was a big ask with no track record.
You can find more detail on it in their post, specifically, the “How will the MWG be compensated” section: Amended- Forming The PT Marketing Working Group