I was using:
curl -v -F file=@/tmp/x.png -F "initial_comment" -F channels='xyz' -H "Authorization: Bearer oauth" https://slack.com/api/files.upload
Got this email from Slack team:
• Support for the files.upload API will be discontinued.
To prepare for this change, we recommend migrating away from files.upload and instead using the combination of files.getUploadURLExternal and files.completeUploadExternal. More information on how to use these two APIs together can be found on our Working with files documentation. You can also leverage Slack’s SDKs to help you transition to this new way of uploading files by visiting our api.slack page.
So, sorry, but it’s unclear what to use instead.
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