How to create price change programmatically?

I'm trying to change subscription prices programmatically and found two relevant API methods:

Create price change

List price points

The first method requires ID of price point that can be retrieved by the second one. The second method returns price points in the following format:

{
    "type" : "appPricePoints",
    "id" : "eyJzIjoiMTU2MTYxMTU2OSIsInQiOiJBRkciLCJwIjoiMTAwNDkifQ",
    "attributes" : {
      "customerPrice" : "3.99",
      "proceeds" : "2.8"
    },
    "relationships" : {
      "equalizations" : {
        "links" : {
          "self" : "https://api.appstoreconnect.apple.com/v3/appPricePoints/eyJzIjoiMTU2MTYxMTU2OSIsInQiOiJBRkciLCJwIjoiMTAwNDkifQ/relationships/equalizations",
          "related" : "https://api.appstoreconnect.apple.com/v3/appPricePoints/eyJzIjoiMTU2MTYxMTU2OSIsInQiOiJBRkciLCJwIjoiMTAwNDkifQ/equalizations"
        }
      }
    },
    "links" : {
      "self" : "https://api.appstoreconnect.apple.com/v3/appPricePoints/eyJzIjoiMTU2MTYxMTU2OSIsInQiOiJBRkciLCJwIjoiMTAwNDkifQ"
    }
  }

where ID of price point is a base64-encoded JSON with three fields: s, t, and p.

I got that Price Changes are pre-created by Apple and I should use them instead of creating my own ones.

So, I tried to send the following request where use base64 itself or every of three values of JSON that is represented as this base64.

{
        "data": {
            "attributes": {
            },
            "relationships": {
                "subscription": {
                    "data": {
                        "id": "subscription-id",
                        "type": "subscriptions"
                    }
                },
                "subscriptionPricePoint": {
                    "data": {
                        "id": <HERE_TRIED_TO_SPECIFY_BASE64_ITSELF_OR_ANY_OF_THREE_VALUES_OF_DECODED_JSON>,
                        "type": "subscriptionPricePoints"
                    }
                }
            },
            "type": "subscriptionPrices"
        }
    }

But every time I get the error:

{
  "errors" : [ {
    "id" : "466aa984-1491-4da3-8e5d-9b26dc9e844f",
    "status" : "422",
    "code" : "ENTITY_UNPROCESSABLE",
    "title" : "The request entity is not a valid request document object",
    "detail" : "Unexpected or invalid value at 'data.relationships.subscriptionPricePoint.data.id'.",
    "meta" : {
      "position" : {
        "row" : -1,
        "column" : -1
      }
    }
  } ]
}

How do I create a new Price Change?