Answer:
(Im assuming this is for class so its formal :))
Dear [friend name],
I have noticed that you have not returned to school for a while. I hope you are doing well and have not caught the coronavirus. We all miss you here at [school name]. You have missed a lot of classes like English, Science and Math. If you have any issues getting caught up, feel free to contact me and I may be able to help you!
Sincerely,
[y/n]
