This came up while I was trying to send emails with attachments in the Gmail API. The attached files are expected as base64 encoded strings along with their content type (eg: image/png). Rather than use the Gmail library on Bubble, I decided to make this possible to do with only the API connector.
This Plugin will take a file url (compatible with the File URL returned from FileUploader’s value’s URL) so you can hook it up with a file uploader or image uploader directly in your Bubble app. And it returns the full base64 string along with just the file as base64 string and the content type as element states. More instructions are on the plugin page.
Plugin Page: File URL to Base64 Plugin | Bubble
Implemented in run-mode: https://blur-apps-playground.bubbleapps.io/version-test/file_to_base64
Try it on the Editor: Blur-apps-playground | Bubble Editor
Hope this helps!