What access is needed for the S3 Put File to work?

I’m making progress with the S3 Put File action. I’ve established it works in PHP v8.1 but not v8.2. (This is already being looked at by the team).

However, I have set a policy in my API key for it to be write only and I’ve established that this is what is giving me a permissions error. The file is uploading to the bucket perfectly but it looks like it needs some kind of read access. If I change the API key to have full access then it works perfectly.

Can someone tell me what permission is needed without actually giving full read access?