Bill API Issue Line item

Hi

When our App sends a bill to Freeagent without line item it exports successfully to Freeagent but as a $0 value item

However when our App adds a line item we are facing the following issue please can anyone help to resolve this.

when we call Freeagent Bill API see below link

https://api.freeagent.com/v2/bills

We get the following error message please advise how we can resolve this.

Error is : “total_value_ex_tax cannot be set at the same time as total_value”

Thanks

SK