Share a private Request for Information (RFI)

Things I have tried publishing - not private
Obsidian publishing - not editable in the browser

What I’m trying to do

I’m a consultant and using Obsidian as a CRM to replace all those bloated SaaS platforms out there - loving it so far.

I need to request information from clients formally and privately and I’m looking for a platform-agnostic solution. Some clients use the Google ecosystem, some Microsoft, some Notion, some Slack, etc. They all allow sharing with other users of the same ecosystem, but it becomes difficult working securely across ecosystems. I can’t ask a Microsoft user to create a Google account just to fill out an RFI form.

What I need is a way to create a .md with all my headings, then share that so the client can edit it in the browser after entering a password.

I know I can just email the client, but I want to have that information in Obsidian alongside my client documents. Also, often the client completes the RFI in stages, so I want to avoid the email chains and the potential to miss something.

I would appreciate any ideas, thanks.