Reflowable ePub Creation & Upload on ingram and Pothi

We have the book ready in both PDF and an earlier ePub draft. I now need a clean, reflowable ePub that passes validation and reads smoothly on every common device. There are no images, audio, or video—just straightforward text that should flow naturally as readers resize their screens... (Budget: ₹600 - ₹1500 INR, Jobs: Adobe InDesign, Amazon Kindle, eBook Design, iPad, Mac OS, Project Management, Publishing, Technical Writing)