Cannot attach dataUri images inline

[orayya-roybh1]

1. What version of the module is the issue happening on? Does the issue happen on latest version?

0.22.0

2. What platform and Node.js version? (For example Node.js 6.9.1 on Mac OS X)

windows, node 11.7.0

3. Does the action work when you manually perform request against mailgun using curl (or other means)?

i dont know

4. Sample source code or steps to reproduce

I could not find a reference

(Write description of your issue here, stack traces from errors and code that reproduces the issue are helpful)

Hi, I am trying to attach a dataUri (string) in an email attachment inline. In Nodemailer for example, you can pass the dataUri string as the image path and it attaches that inline (requires CID input).
How can I attach a dataUri image inline? (base64). thanks