Id second the s3 idea as youre hosting data for professional reasons. Backblaze and cloudflare also offer s3 compatible storage, when i priced them up for work cloudflare was by far the cheaper option. But iirc their s3 api is still under development and is not ( at the time i used it) feature complete. We had some trouble generating pre-signed urls. But if you just want some place to store data these are worth a look

Paperless might be what you want