To access the Graph Explorer, visit: https://developer.microsoft.com/en-us/graph/graph-explorer

Sign in using your Entra account

Change the HTTP method from "GET" to "PATCH", and change the endpoint to "https://graph.microsoft.com/beta/directory/authenticationMethodDevices/hardwareOathDevices"

Click the "Modify Permissions" 

Grant consent for the "Policy.ReadWrite.AuthenticationMethod" permission

Click the "Request body" tab

Open the JSON file in a text editor, copy all the contents, and paste the data into the Request body 

Click the Run query button.

If you see "OK - 200 - ...", then the tokens have been successfully uploaded into the Token Resposiroty in your Entra ID tenant.

To check your Token Repository in Entra ID, you must also use the Graph API.

You can now give the tokens to your users and ask them to self-enroll their tokens in Entra ID