ftx_modify_order_clientid() should have an additional parameter new_client_id that should be passed to API in post body as clientId. Otherwise, the modified order is not accessible by client_id,
Change clientId parameter by client_id in ftx_place_order function. Then the naming convention is consistent over all functions where client_id is used.
ftx_modify_order_clientid() should have an additional parameter new_client_id that should be passed to API in post body as clientId. Otherwise, the modified order is not accessible by client_id,