Hi @Anonymous,
What is the trigger in your flow?
You could add a "Manually trigger a flow" trigger in your flow, and add an input of file type as screenshot below:
And when you run the flow, you will be required to choose a file to input, you could choose the image that you mentioned, and then the flow would run successfully to send the email with the image as attachment.
If you have another trigger in your flow, you could save the file in your sharepoint or onedrive for business, and then get the file content of the image, finally you could send the email.
Best regards,
Alice
