I’d probably reach for an AWS S3 bucket for this sort of thing.
I believe S3 is free for small uses, and pretty cheap otherwise, and their docs are pretty solid IIRC.
EDIT
Second Edit:
AWS Free Usage Tier* As part of the AWS Free Usage Tier, you can get started with Amazon S3 for free. Upon sign-up, new AWS customers receive 5GB of Amazon S3 storage in the S3 Standard storage class; 20,000 GET Requests; 2,000 PUT, COPY, POST, or LIST Requests; and 15GB of Data Transfer Out each month for one year.