I have this sample request with cUrl in the contract (the contract docs only show this for the endpoints):

curl 
    -X PUT 
    -H 'Content-Type: application/octet-stream' 
    -H 'Content-Disposition: attachment; filename=file.pdf 
    --upload-file my-file 
    https://storage.google.apis.com/…..

The endpoints intended to update an image. I have only an image in the base64 string format, and I want to upload this data through this endpoint.

1. Since the API docs only provide that information, should I directly pass the base64 string as the request body as below:

const dummyBase64Image = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABgAAAAYCAYAAADgdz34AAABjElEQVRIS+2VvUoDQRSGv9V2'

fetch(
    'https://storage.google.apis.com/…',
    {
        method: 'PUT',
        headers: {
            'Content-Type': 'application/octet-stream',
            'Content-Disposition': 'attachment; filename="dummy.js"'
        },
        body: dummyBase64Image,
    }
)..... // callback handling

Or should I parse the image with the base64 string format into another form (such as parse the base64 string into binary format)?

2. Is the request sample with cUrl and content-type: application/octet-stream in the documentation enough to conclude that the request body form must be mere a base64 string format (fetch chaining shown above)and not like the usual object that is being passed in the request body with some predetermined field name such as (below fetch chaining):

fetch(
    'https://storage.google.apis.com/…',
    {
        method: 'PUT',
        headers: {
            'Content-Type': 'application/octet-stream',
            'Content-Disposition': 'attachment; filename="dummy.js"',
        },
        body: {
            image: dummyBase64Image,
        }
    }
)..... // callback handling