Generate dinamyc image for requests in google cloud in real-time

Question

I would like to know how to edit an image in real time when a user makes a request, that is, dynamically display the image to a user.

I have a system that needs to show a certain image with a specific watermark for each user that the image appears on.

I use Google Cloud Storage to save my images.

Is there any way to do this with Google Cloud? If not, what other services can make this available to me?

I want to avoid developing a server-side application from scratch to solve the problem.

I've seen that you can edit an image on Google Cloud after it's been uploaded. But that doesn't work, I need it to render in real time to user requests.