If you haven't brought aws yet. They provide 1 year free service, check if its available.

Then deploy your server side API code using lamda and serve users from that layer(Read abt serverless architecture, u don't need an ec2 instance). Which is relatively cheap, its pricing is based on number of times it runs, if i remember correctly they give 1 million free call per month i guess, even if its not, its pricing is relatively cheap.

And store the images in s3.