Dear Sir/Madam,
I am writing this application to inform you that I have forgotten my ID card at home today. I am extremely sorry for this inconvenience and I understand that it is important to carry the ID card at all times as it serves as a means of identification and security.
I assure you that this is a one-time mistake and I will ensure that I carry my ID card at all times in the future. I request you to kindly grant me permission to enter the premises for today and I promise to submit my ID card at the earliest.
Thank you for your understanding and cooperation.
Sincerely,(your name right here)