You use the first person throughout.
Yes, I can provide you with a reference letter for your job application.
Yes, I can provide a family reference letter for your job application.
Yes, we can provide family reference letters for your job application.
Yes, I can provide you with a letter of reference or recommendation for your job application.
I am happy to provide a positive reference letter for your job application.
Yes, you can request a reference from Professor Sample for your job application.
Yes, I can provide a reference letter from my professor for my job application.
Certainly, I would be happy to provide you with a reference letter for your job application.
I suppose you can, but you will not get the job.
go to reference
I am happy to provide you with a reference letter for your job application. Please let me know the details you would like me to include in the letter.
Yes, please provide three letters of recommendation for the job application.