create a sales agreement, you need to specify the account, the price book, and the product(s) that are part of the agreement. The account is the customer that you have a contractual relationship with. The price book is the list of products and prices that you offer to the account. The product(s) are the items that you agree to sell to the account for a certain quantity, price, and time period.You can also add other optional data elements to the sales agreement, such as start date, end date, schedule frequency, schedule count, and terms and conditions1.Reference:

Create a Sales Agreement