hi immanuel,
yes, they could upload the document to your sharepoint online library. to do that:
1. if you are the global admin, log into the team site, click the gear on the upper right corner> select
site contents > click **add an app>create a document library> open the library>**click the **library on the top menu bar.> click the icon!\[\](http://fud.community.services.support.microsoft.com/Fud/FileDownloadHandler.ashx?fid=3c2f934a-b762-48d2-9f88-e36fcba3f2aa)****on the right side to share the library >**click advanced under shared with> click **stop inheriting permissions>**click **grant permissions>**enter the user's email address, select a contributepermission and click share.> let the user check the mailbox and accept the invitation.****if the user has no office 365 work or school account, he can sign into the shared link with a microsoft account to upload the document.
- if you are not an admin, you may share your onedrive for business library with the users referring the steps above. as the onedrive for business library is private as default, it is not recommended to share it with others.
note: before you share the library, you may let the admin make sure the external sharing is enabled on the tenant and the site collection referring to
manage external sharing for your sharepoint online environment.
thanks,
felix