Uploading a file via the Slack module as a bot

Hello everyone! I'm new to this community.

I've encountered a problem that I haven't been able to resolve, so I'm reaching out to the community for assistance.

I'm setting up a workflow where a voice message from Slack is transcribed into text, processed by an AI agent, and the resulting response is converted back into audio and sent as a reply within Slack.

Everything functions correctly, with the exception of the final step: uploading the file back to Slack.
Even though my bot has all the necessary permissions, the Upload a file module doesn't provide an option to send the file as the bot (unlike the message module).
Even when I input the bot's Client ID and Secret, the file is still uploaded as if I initiated it, not the bot.

Has anyone else experienced this issue?
Is there a way to upload a file as the bot?
Or perhaps this is a known limitation in callin.io at the moment?

Thank you in advance to anyone who can offer help.