Test Report Generation [closed]

I have a use case to write code to test some functionality and then generate report in a File. To do this i have an api exposed which will take some inputs(string) and then should return the downloadable result file. Am using API Gateway + Lambda for this use case. Now after running tests , am pushing the collected information(pass/fail, error message, req and response) in the string list.

My question is how should i push all those collected information in a file(text or pdf) and then return that as an api response.

Thanks in advance!