Is it possible to return .PDF file from API to download?

I'm working on a legacy project that need a new function on Lumen API to make .PDF file from image (.PNG).

This process is already handled by plain PHP and FPDF library from legacy code (.PNG file is stored on server, .PDF file after processed will also be stored on server).

But now I need to refactor it by using Lumen.

This new API will be called by Angular application to download the PDF file to customer's computer.

So ... is it possible to return a .PDF file in response so that when Angular called, a .PDF file will be downloaded?

Thank you very much.