I want to know that whether there is any way to configure disaster recovery for SharePoint Online. Can we restore crashed files or store the SharePoint files in some server? If there is a way, please tell me how to configure it.
Disaster recovery is something that Microsoft takes care of. DR generally refers to the loss of a physical location.
It sounds like what you're asking about is backups. While Microsoft provides a full site backup for 14 days, if you want a cloud backup solution you'll want to look at 3rd parties, which there are many of so I won't make any specific recommendations. I would suggest searching for 'SharePoint Online cloud backup'.