Unknown options: s3://***/ error

[BMETtoIT]

I keep getting this error even though I have my S3 bucket name in my Github Actions Secrets without the "s3://" part. I believe I have the correct bucket policy too, so I'm not sure what the issue is.

This is my bucket policy:

{
    "Version": "2012-10-17",
    "Id": "PolicyForPublicWebsiteContent",
    "Statement": [
        {
            "Sid": "PublicReadGetObject",
            "Effect": "Allow",
            "Principal": {
                "AWS": "*"
            },
            "Action": "s3:GetObject",
            "Resource": "arn:aws:s3:::bucketname/*"
        },
        {
            "Sid": "s3actionsync",
            "Effect": "Allow",
            "Principal": {
                "AWS": "*"
            },
            "Action": [
                "s3:PutObject",
                "s3:GetObject",
                "s3:ListBucket",
                "s3:DeleteObject",
                "s3:PutObjectAcl"
            ],
            "Resource": [
                "arn:aws:s3:::bucketname",
                "arn:aws:s3:::bucketname/*"
            ]
        }
    ]
}

And this is the script:

name: Upload Website

on:
  push:
    branches:
      - main

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@master
      - uses: jakejarvis/s3-sync-action@master
        with:
          args: --acl public-read --follow-symlinks --delete
        env:
          AWS_S3_BUCKET: ${{ secrets.AWS_S3_BUCKET }}
          AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
          AWS_REGION: 'ap-northeast-1'
          SOURCE_DIR: 'Resume Website'