fix access token generation key

Author: der3318

articles/ai-services/computer-vision/how-to/identity-access-token.md

@@ -57,7 +57,7 @@ To call the **issueLimitedAccessToken** API, copy the following cURL command to
 
 ```bash
 curl -X POST 'https://<isv-endpoint>/sts/v1.0/issueLimitedAccessToken?expiredTime=3600' \  
--H 'Ocp-Apim-Subscription-Key: <client-face-key>' \  
+-H 'Ocp-Apim-Subscription-Key: <isv-face-key>' \  
 -H 'Content-Type: application/json' \  
 -d '{  
     "resourceId": "/subscriptions/<subscription-id>/resourceGroups/<resource-group-name>/providers/Microsoft.CognitiveServices/accounts/<face-resource-name>",  
@@ -68,7 +68,7 @@ curl -X POST 'https://<isv-endpoint>/sts/v1.0/issueLimitedAccessToken?expiredTim
 Then, make the following changes:
 1. Replace `<isv-endpoint>` with the endpoint of the ISV's resource. For example, **westus.api.cognitive.microsoft.com**.
 1. Optionally set the `expiredTime` parameter to set the expiration time of the token in seconds. It must be between 60 and 86400. The default value is 3600 (one hour).
-1. Replace `<client-face-key>` with the key of the client's Face resource.
+1. Replace `<isv-face-key>` with the key of the ISV's Face resource.
 1. Replace `<subscription-id>` with the subscription ID of the client's Azure subscription.
 1. Replace `<resource-group-name>` with the name of the client's resource group.
 1. Replace `<face-resource-name>` with the name of the client's Face resource.