To automatically assign incoterm to an EasyPost shipment, create a shipping rule by navigating to the Shipping Rules page and selecting Add rule.
Set the filtering criteria that will trigger this rule to apply, such as when the buyer requests a particular method or lives in a certain country. Using "Shipping method requested" as the criteria is useful, particularly if the requested method describes the kind of incoterm the recipient requested.
Next, set the Action that will occur when the the criteria you set above is met and the rule triggered. Select "Set customer incoterm (Easypost)" and the desired incoterm.
Repeat this process for each type of incoterm you offer to your customers, creating at least one separate rule for each type.
Important Note: according to Easypost, "Setting [incoterm] to anything other than "DDP" will pass the cost and responsibility of duties on to the recipient of the package(s), as specified by Incoterms rules."