When creating your campaign, go to "Delivery" to choose how Roku will bid on advertising opportunities within your campaign parameters.
Your previously selected advertising objective and optimization goal will appear there, as well, but you can change them using the Edit button.
Choose 1 of 2 bid options: Auto bid or Max bid
Auto bid: this tells Ads Manager to optimize your bids based on your advertising objective. This is the default option and doesn’t require any input from you.
Max bid: this allows you to set a maximum bid, which tells Ads Manager the most you want to bid on an opportunity.