Respected Sir/ Madam,
I write this email in reference to the job opportunity that I am being offered at your reputed school. I am glad to inform you that my resume is shortlisted for the ____________ (teacher/ designation) at your reputed school for which I was asked to attend an interview on __/__/____ (date).
But, unfortunately, I will not be able to attend the interview as __________ (mention reason) therefore, I write this email to request you to kindly reschedule the interview to __/__/____ (date) or any other date. I shall be highly obliged for your kind support.
For further queries, you may contact at __________ (mention contact details).
Thanking you,
Sincerely,
_________ (your name),
_________ (contact details)