First of all, there is a difference between coconut milk and coconut juice. Coconut milk is a white liquid extracted from coconut meat. This liquid is very rich. Generally, coconut milk sold in shopping malls or supermarkets cannot be directly drunk. It needs to be diluted according to the proportion on the outer packaging instructions before drinking. Coconut juice can be drunk directly after being bought in the supermarket. Under normal circumstances, the made poplar nectar is made from diluted thick coconut milk, because the taste of this kind of poplar nectar will be stronger than that made from coconut milk. If you use light coconut milk, you can omit the dilution step and make it directly.
Everyone has different taste requirements for drinks. Some people like a strong taste or a sweet taste, while others like a light taste. There is no standard answer to whether to use coconut milk or coconut juice to make poplar nectar. If you have a friend who likes light taste, you can also try to use coconut juice to make poplar nectar. Maybe it has a different flavor!