I need a website which auto watermark image with given png logo

I would need a simple website where:

- you open the website there is a pic upload form (jpg,png)
- upload picture
- we collect email and phone number in exchange of watermarking
- then website automatically place a given PNG watermark on picture (such as on pictures of this post) - Cutomer provides their pic, i will provide the PNG
- then customer can download the picture with watermark added.