Leaving S3 is a config change,
not a rewrite.

1# Before — AWS S3
2s3 = boto3.client(
3    "s3",
4    region_name="us-east-1",
5)
6
7# After · Fil One (no other changes)
8s3 = boto3.client(
9    "s3",
10    endpoint_url="https://eu-west-1.s3.filonecontent.com",
11    aws_access_key_id=os.environ["FIL_ACCESS_KEY"],
12    aws_secret_access_key=os.environ["FIL_SECRET_KEY"],
13    region_name="eu-west-1",
14)

1// Before — AWS S3
2const s3 = new S3Client({ region: "us-east-1" });
3
4// After · Fil One
5const s3 = new S3Client({
6  endpoint: "https://eu-west-1.s3.filonecontent.com",
7  region: "eu-west-1",
8  credentials: {
9    accessKeyId: process.env.FIL_ONE_ACCESS_KEY,
10    secretAccessKey: process.env.FIL_ONE_SECRET_KEY,
11  },
12});