Howto add onedrive for business to file explorer

Hey there, I was looking for the same thing because I was unable to find the OneDrive for my business account too. I believe the solution you are looking for is in the following link:

Sync files with OneDrive in Windows (microsoft.com)

If you get a error telling you that OneDrive is already installed. Even better. Because that means you only need to add the Microsoft365 or Office365 account. 

To add the account to the existing OneDrive installation hover your mouse over the taskbar.

Step 1. Click the OneDrive icon next to the clock.
Step 2. Click "Help & Settings" and click "Settings" from the drop-down menu
Step 3. Microsoft One Drive properties pop up will appear. Click Add account.

The OneDrive icon for the second account will appear on the taskbar next to the personal OneDrive icon. 

I hope this helps you and resolves your issue Pepijn van Beusekom