Need Help Crafting a Casual Leave Email for My Cousin's Wedding in Bangalore

Hi friends, I need your help. I want to attend my cousin's marriage in Bangalore and will need a casual leave for three days. I have already sent a request email to my manager or head. Can you please guide me on what I need to include in the email? I would appreciate it if you could provide me with a sample letter or email to send. Thank you.

Dear Sir,

Please let me know how to apply for leave to request permission to celebrate the New Year festival. Could you kindly send me the required format to my email address?

Thank you.

Dear sir,

I have to send a request email to my manager for 2 days of leave. Could you please provide me with a 2-day leave letter?

Regards,
Visual Securas

I want to attend my cousin's marriage and I want to take leave for 10 days. Please provide me with the letter format that I can send to my manager and supervisor.