Fabric API: Update user scopes

Context: The token I generated was retrieved by logging in with 'Login-PowerBI', followed by "Get-PowerBiAccessToken -asstring" inside of Powershell. This token was then copied and used inside of postman for the authorization. I didn't use any extra parameters. Since the current usage of a Service Principal is quite limited for the Fabric API, we're opting to use the personal bearer token.

Scenario: At our company we're trying to experiment a bit with the MS Fabric API (https://api.fabric.microsoft.com). With the service principal token, we've been able to use the API to list the workspaces, items, ... basically most standard get calls you could imagine. But, it doesn't support creating items yet via the service principal. So, we had to switch to the usage of a personal user token.

We are able to create workspaces via my individual token, but I'm unable to create individual items inside of a workspace. This is due to the fact that I don't have any individual item level scopes assigned to me for now. My current scopes are: "App.Read.All Capacity.Read.All Capacity.ReadWrite.All Content.Create Dashboard.Read.All Dashboard.ReadWrite.All Dataflow.Read.All Dataflow.ReadWrite.All Dataset.Read.All Dataset.ReadWrite.All Gateway.Read.All Gateway.ReadWrite.All Pipeline.Deploy Pipeline.Read.All Pipeline.ReadWrite.All Report.Read.All Report.ReadWrite.All StorageAccount.Read.All StorageAccount.ReadWrite.All Tenant.Read.All Tenant.ReadWrite.All UserState.ReadWrite.All Workspace.Read.All Workspace.ReadWrite.All"

As you can see, it's quite normal that I'm only able to create a Workspace. But I want to be able to assign e.g. "Notebook.ReadWrite.All" to my user. How do I do this for an individual user? I'm trying to automate as much as possible using Powershell scripts, but the current scopes are quite limited.

Goal: Using a personal bearer token (not generated through a service principal) to create a notebook item. Endpoint: https://learn.microsoft.com/en-us/rest/api/fabric/core/items/create-item?tabs=HTTP 

Question: Is it possible to do this without the usage of a service principal? I know you can use the copy(PowerBIAccessToken) inside of the dev-tools in your browser, but I want to do it more automatically.

Hopefully this is the right section to ask such things, and thank you in advance for your help!