You can create rules in DHL Express Commerce based on the value of an order.
For example, if you want a signature to be collected on delivery if the value of the items in the order is greater than 100 dollars, you can set up a rule to automatically enable Signature Required.
How to set up the rule
In DHL Express Commerce, navigate to Settings > Rules.
Select Add a new rule.
Under Condition(s) select Order Value.
Under Action select the action relevant to you. e.g. Set Signature Required: True.