Appointment Letter Formats: How Do You Draft for Security Guards and Fixed-Term Employees?

Please provide the appointment letter format for security guards and fixed-term employees.

Hello there, I want to know if a person has received an offer letter and now, after the successful completion of his or her probation period, the company is appointing him or her, what formalities need to be completed. What should be mentioned in his or her appointment letter? If you have any format, please provide. Any guidance you can offer will be greatly appreciated.