Unsigned headers for direct uploads

Hi there,

I am trying to use CloudFlare R2 for uploads. Using direct uploads, I keep getting error 403. This is because, Cloudflare R2 does not support signing headers, and direct upload, generates a url like this:

https://<BUCKET_NAME>.<ACCOUNT_ID>.r2.cloudflarestorage.com/xxxxx?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=xxxx%2F20221031%2Fauto%2Fs3%2Faws4_request&X-Amz-Date=20221031T110341Z&X-Amz-Expires=300&X-Amz-SignedHeaders=content-length%3Bcontent-md5%3Bcontent-type%3Bhost&X-Amz-Signature=xxxxx

Is it possible to disable signed headers? Is it secure?