I have added this request to the tracker:
Issue 2089 – Allow S3 connection with IAM role instead of credentials
You can vote for it there.

This would definitely be very helpful.

Thanks for your suggestion.
Quick research did not get me any information on the API needed to implement this. Will have to look into this deeper later.
And we will see, if more people ask for this.

Exactly! And the feature request is to be able to use AWS Role instead of Profile.

WinSCP can read AWS credentials from the AWS profile file:
https://winscp.net/eng/docs/ui_login#read_credentials

When S3 connection runs on AWS instance (called EC2), it is best practice to *not* use the credentials but use instance profile instead. Unfortunately, this scenario is not supported in WinSCP – it requires the user to enter Access and Secret Keys. CLI command would look the same: without requiring credentials

It would be really nice to not require the user to enter credentials!

Thank you

UPDATE: Sorry, while I wrote correctly in the subject of the post, I should have said instance role rather than instance profile. Sorry for the confusion