I sent a message in a chat asking if uploading or attaching a file in a form was possible (after checking all the widgets). Apparently it is not available. Was asked to post here. I will expand the use case for better context.
The need for file attachment is for a support form or post / send / request. Fill in a form with name, email , description and attach file or screen shot.
I also use another product, which has this feature. The attachment is not actually attached to the email ( there are many potential issues, e.g. file size, malicious files etc ). The other platform sends the attachment to a area and provides a link to download the file in the email. They also have in the field setup a file type specification, so I can restrict the attachment type, e.g. has to be a .pdf or .jpg. File size might be an a good option to add.
Please add this to roadmap if it is not already on.