When you are on low-carb diet but you’re still hungry or craving or still have an appetite, there’s five reasons why this would be happening.

You are not doing keto fasting in a right way, you might be eating too frequently, in keto low carb diet you must stick to the schedule, whether you are eating foods on low-carbs, high in protein or high in fat. You are consuming foods too frequently all these triggers insulin hormone. This would be like fueling the fire, this insulin hormone is going to make you hungry. Keto is all about keeping your stomach offline for long.
Hidden carbs: You might be eating some packed keto friendly foods, which they say low carbs but they may not be so.
You may not be consuming low Dietary Fat, you want to increase the fat to satisfy you and also so you can fast longer.
Its not working, Your body may not be transition from glucose to ketones, in general 3 days on low-carbs, High fat and protein diet must switch body to generate ketone from Fat. Wait more couple for days, check weather you might be doing incorrectly or not.
When you are on diet, you are disconnecting the main source of nutrients and minerals to the body, make sure you are consuming low carbs with enough nutrients and minerals required. You can consume nutrients, minerals multivitamins supplements.