Macros or calories?

You will.

Calories determine weight loss, especially in the short run.

Macros are for nutrition, health, energy level, satiation, body composition (muscle especially).

Over the long term, very bad nutrition (including very far from adequate macros) might hurt energy level, so reduce your activity, thus burn slightly fewer calories. That could affect weight loss.

Or, macros that aren't right for you can affect satiation and satisfaction with your eating, making it hard to stick with your calorie goal. That could affect weight loss.

But mostly, weight loss is about calories.

For nutrition and health, close on macros is fine: You don't need to be exact.