First, you have to create an account in OneDrive for Business.

If the OneDrive for business account is inside an organization, it needs to have administrator rights to be able to connect with 3rd party applications or the administrator must give the user account rights to use 3rd party applications.

Follow the steps on the link below to grant the rights:https://support.office.com/en-us/article/Turning-Integrated-Apps-on-or-off-7e453a40-66df-44ab-92a1-96786cb7fb34

Then, you can enter your password and user in Air Explorer and start to work with it.

You can check more information here:
-pCloud in Air Explorer
-Strato HiDrive in Air Explorer
–MagentaCLOUD in Air Explorer
-Mail.com in Air Explorer