> As far as I could tell, the only way to provision an application was through a mobile phone app.
Any application that knows how to ingest an otpauth:// URL and generate TOTP tokens will work. I know that 1Password on macOS does, and I suspect that other desktop password managers also have TOTP support.
> I don't have anything that can scan a QR code.
If you open the HTML for the TOTP provisioning page, you'll find the raw otpauth:// URL in an "aria-label" attribute on the QR image. That's obviously not very user friendly, and will be improved upon.