What to write in the cover letter?

Would like to apply for this Admin job that has HR duties but I don't have any knowledge of HR or HR work related experience. My previous jobs were all administrative in nature. I haven't done any of what is stated below. Job says - Minimum 5 years admin experience.

Job description :

General Administrative duties include but not limited to ensuring day-to-day efficient operations of the office, meetings preparation, office logistics, purchasing of office / pantry-related items, processing monthly expense claims as well as processing payments to suppliers.

HR duties include but not limited to recruitment, new employee orientation, staffing logistics, maintaining employee and leave records, generating monthly staff productivity reports, calculating staff incentives as well as conceptualizing and organizing company activities and events for staff development.

Please give me some ideas on what to write in my cover letter? Should I say - although I lack HR knowledge, I am very eager to learn if given the opportunity, sign up for course later?

Please don't refer me to websites. Thanks.




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