diff --git a/download.sh b/download.sh
index 4792cce..4543762 100755
--- a/download.sh
+++ b/download.sh
@@ -1,5 +1,7 @@
 #!/bin/bash
 
+# .env contains a line like
+# BASE64_ENCODED_BEARER_TOKEN='<literal base64 encoded string>'
 source .env
 OUTFILE_PATTERN="./videos/video_INDEX.mp4"
 API_URL='https://euwe-1.api.microsoftstream.com/api/videos?'\