Use the MSGraphClient to connect to Microsoft Graph

I've followed all the step in this article:

https://docs.microsoft.com/en-us/sharepoint/dev/spfx/use-aad-tutorial

to secure an AZURE function and call it from my developer Office 365 tenant,

 when i upload the sppkg web part i've the message: error in the application

and i'm not able to see the link API Management in the new SharePoint central administration

Any help ? thank you