This P is likely the one you expected from the get-go: promotion entails any online or print advertisement, event, or discount your marketing team creates to increase awareness and interest in your product, and, ultimately, lead to more sales. During this stage, you'll likely see methods like public relations campaigns, advertisements, or social media promotions.
This refers to how the product gets to the customer; the distribution channels and intermediaries such as wholesalers and retailers who enable customers to access products or services in a convenient manner. This third P has also sometimes been called Place or Placement, referring to the channel by which a product or service is sold (e.g. online vs. retail), which geographic region or industry, to which segment (young adults, families, business people), etc. also referring to how the environment in which the product is sold in can affect sales.  5 Digital Marketing Skills to Master for 2020 & Beyond