SignatureDoesNotMatch PUT-ing to SignedUrl using ActiveStorage

Hello,

I am currently trying to implement an image upload feature within the application I’m working on and trying to take advantage of Rails ActiveStorage and DigitalOcean Spaces.

I am generating a presigned-url from ActiveStorage and from that URL I am trying to test an upload with it using Postman.

My config/storage.yml file looks like so:

digital_ocean:
  service: S3
  endpoint: https://nyc3.digitaloceanspaces.com
  access_key_id: XXXX
  secret_access_key: XXXX
  region: nyc3
  bucket: XXXX
  public: true

I have updated the config/environments/development.rb file to use this service

config.active_storage.service = :digital_ocean

Since I am trying to get this to work on development first I have used s3cmd to configure CORS for my Space.

<CORSConfiguration>
  <CORSRule>
    <AllowedOrigin>http://localhost:3000</AllowedOrigin>

    <AllowedMethod>GET</AllowedMethod>
    <AllowedMethod>POST</AllowedMethod>
    <AllowedMethod>PUT</AllowedMethod>
    <AllowedMethod>DELETE</AllowedMethod>
    <AllowedMethod>HEAD</AllowedMethod>

    <AllowedHeader>*</AllowedHeader>
  </CORSRule>
</CORSConfiguration>

Using Postman, I POST to an endpoint within my application to generate a presigned-url which gets returned.

The idea is that the front-end portion of my application would PUT to this URL.

I then try to PUT to it, setting the binary to a file I wish to upload, each time I submit, I get the following 403 Forbidden back:

<?xml version="1.0" encoding="UTF-8"?>
<Error>
    <Code>SignatureDoesNotMatch</Code>
    <RequestId>tx000000000000032e92095-0060ad32dc-c814494-nyc3c</RequestId>
    <HostId>c814494-nyc3c-nyc3-zg03</HostId>
</Error> 

Any and all help would be greatly appreciated

Thanks in advance