Hi Bharat!
Trade on Candle Completion feature is provided as a savior against false signals. Most of the AFLs available online are prone to repainting issues so this acts as a confirmation step.
However, if the AFL you are using is well coded and there are no repainting issues, it is not compulsory to trade on candle completion. You can use Trade Intrabar in that case.
Let us know if you have any other questions.