No beep sounds when the ignition is turned on

Greetings Friends
When he turned the ignition, he waited for a few seconds before starting the car and started the car when he heard the beep. I can't hear that sound for a week. What is the problem? There is no problem in other warnings.

Normally, he shouldn't give that warning anyway. If the beep beeps three times when the ignition is turned on, the gasoline is low warning. It will not warn you if you have bought gasoline. Normally there is no warning alert if there is no problem

It gives a low warning of fuel with light. Normally, when he turned the contact and gave the electricity, he would give it 6-7 seconds later. He gave me a fuel today, he did not have fuel