private String removeFipsIfNeeded(String region) {
        if (region.startsWith("fips-")) {
            return region.replace("fips-", "");
        }

        if (region.endsWith("-fips")) {
            return region.replace("-fips", "");
        }
        return region;
    }
It should redirect signer if the request is CreateBucketRequest or ListRegionalBucketsRequest with outpostId present
aws-java-sdk-s3control/src/main/java/com/amazonaws/services/s3control/internal/handlers/EndpointHandler.java