Hi,
"Microsoft.Office.Interop.Excel" cannot be used without having Office installed.
Installing Office in App Service is not supported
You can either host your function on a VM or use something like OpenXML (https://github.com/OfficeDev/Open-XML-SDK) with ClosedXML (https://github.com/ClosedXML/ClosedXML) to edit Excel files.
(this is based on my knowledge by july 13th 2022)