Hi, Is it possible to backup all data from our Quickbooks Primier 2018 to our Quickbooks online?

Thank you for trusting QuickBooks in keeping your company data, @useraccountant2.

To clarify, are you referring to move your QuickBooks Desktop (QBDT) data to QuickBooks Online (QBO)? If yes, I'd be glad to share with you the steps to do this:

1. Make sure your QBDT program is updated to its latest release and then, check your file size.
2. Once done, go to the Company menu, then choose Export Company File to QuickBooks Online.
3. Select Start your export.
4. Then, sign in as an admin to your QBO company.
5. If you track inventory in QuickBooks Desktop, choose Yes to bring them over. Then, No if you want to start new in QBO. 
6. Click the Choose online company dropdown, and choose the QBO company you want to be replaced by your company file.
7. Then, Continue and type “Agree” in the text field, then select Replace.
8. Click Yes, go ahead and replace the data. Then, Replace.

For more info about this process, please visit this article: Move your QuickBooks Desktop file to QuickBooks Online.

Also, I got you this useful link to provide more details on how your QBO data is backed up: Do I need to back up my data with QuickBooks Online?

If you're looking for resources or articles you can bookmark or save for future use, you can always visit our QuickBooks Help articles page. You can manually search via entering a keyword on the search field or open any of the categories displayed to start browsing.

Please know that I'm always here if you have further concerns about creating a backup of your company data. I'd be happy to lend you a hand. More power to your business. 

@useraccountant2 

Just to clarify your query. What do you mean with "backup"? Do you need to migrate data from QB Desktop to QB Online, or do you need to access your QB Desktop file by internet connection similar with QB Online? Where is your company located?