Send email with attachments fails

I have created a simple app to send emails with attachments on my Self-hosted Retool.
I have tried to upload files using all possible options in retool (File Button, File Input and File Dropzone), but when I try to send the uploaded file in the attachments using SMTP query, I get an error undefined is not a function

It seems this feature does not work File Dropzone + Email Query Error - "Use File Picker to upload a file and ensure file is uploaded before query is fired." - #5 by Tess
Do you have any workarounds?
Thank you.

Hey @ivanfreiuk!

It looks like this may be related to a known issue with the SMTP integration. We can let you know here when it has been resolved, but, in the meantime can you try using fx mode:

and passing in the following:

[{data: {{fileInput1.value[0]}}, name: {{fileInput1.files[0].name}}, contentType: {{fileInput1.files[0].type}} }]