How much data? How often does it change? A common pattern is software like Restic saving to any S3 compatible service. There are quite a few, but one of the common, and affordable, one is B2 from backblaze.

You also did not mention what OS. The options for windows are very different from what you can get for Mac / Linux. Many of the Linux options are able available for Mac and Mac has some options of it’s own which are Mac only.

Without even the most basic info about your setup and what you are trying to backup it is hard to give anything beyond generic suggestions.