Addding Form responses to Sharepoint list

Question

I'm new to the whole Microsoft Office 365 ecosystem, and I'm working on a new project. There I need to get personal information and documents from people outside my organization and fill Sharepoint list with them. The problem is that in Microsoft Forms you cannot upload a file if you are not already in the organisation and other form apps (f.e. Google Forms) don't have integration with Sharepoint. I have tried to do write a webhook for google forms, but it stores documents in Google Drive which I don't want. If you know how I can solve this issue, your help will be very much appreciated.