FIXUP: Improve s3access documentation

docs/s3access.md

@@ -69,8 +69,9 @@ for more information on how to use your temporary credentials.
 
 This example lambda function uses
 [EDL Bearer Tokens](https://urs.earthdata.nasa.gov/documentation/for_users/user_token)
-to obtain s3 credentials and stream an object from one bucket to another. The lambda
-execution role will need permissions to upload to the destination bucket.
+to obtain s3 credentials and stream an object from one bucket to another. The
+lambda execution role will need `s3:PutObject` permissions on the destination
+bucket.
 
 
 ```python
@@ -81,10 +82,10 @@ import urllib.request
 
 def lambda_handler(event, context):
     # Get temporary download credentials
-    tea_url = event["TeaUrl"]
+    tea_url = event["CredentialsEndpoint"]
     bearer_token = event["BearerToken"]
     req = urllib.request.Request(
-        url=f"https://{tea_url}/s3credentials",
+        url=tea_url,
         headers={"Authorization": f"Bearer {bearer_token}"}
     )
     with urllib.request.urlopen(req) as f:
@@ -116,7 +117,7 @@ The example can be invoked with an event payload as follows:
 
 ```json
 {
-    "TeaUrl": "https://your-tea-host/",
+    "CredentialsEndpoint": "https://your-tea-host/s3credentials",
     "BearerToken": "your bearer token",
     "Source": {
         "Bucket": "S3 bucket name from CMR link",