diff --git a/check_stereo/main.ts b/check_stereo/main.ts
index 0705c1b..0a42b90 100644
--- a/check_stereo/main.ts
+++ b/check_stereo/main.ts
@@ -21,6 +21,7 @@ document.addEventListener("DOMContentLoaded", async () => {
     channelIdSuffix,
     secretKey,
   );
+
   const recvonly = new RecvonlyClient(
     signalingUrl,
     channelIdPrefix,
diff --git a/recvonly/main.ts b/recvonly/main.ts
index 3c7ca76..7279bbe 100644
--- a/recvonly/main.ts
+++ b/recvonly/main.ts
@@ -10,7 +10,7 @@ document.addEventListener("DOMContentLoaded", () => {
   const signalingUrl = import.meta.env.VITE_SORA_SIGNALING_URL;
   const channelIdPrefix = import.meta.env.VITE_SORA_CHANNEL_ID_PREFIX;
   const channelIdSuffix = import.meta.env.VITE_SORA_CHANNEL_ID_SUFFIX;
-  const secretKey = import.meta.env.VITE_SORA_SECRET_KEY;
+  const secretKey = import.meta.env.VITE_SECRET_KEY;
 
   // Sora クライアントの初期化
   const client = new SoraClient(
diff --git a/replace_track/main.ts b/replace_track/main.ts
index efc021e..6b15442 100644
--- a/replace_track/main.ts
+++ b/replace_track/main.ts
@@ -21,7 +21,7 @@ document.addEventListener("DOMContentLoaded", async () => {
   const signalingUrl = import.meta.env.VITE_SORA_SIGNALING_URL;
   const channelIdPrefix = import.meta.env.VITE_SORA_CHANNEL_ID_PREFIX || "";
   const channelIdSuffix = import.meta.env.VITE_SORA_CHANNEL_ID_SUFFIX || "";
-  const secretKey = import.meta.env.VITE_SORA_SECRET_KEY || "";
+  const secretKey = import.meta.env.VITE_SECRET_KEY || "";
 
   const client = new SoraClient(
     signalingUrl,
diff --git a/sendonly/main.ts b/sendonly/main.ts
index 0dced7e..8ccd7ab 100644
--- a/sendonly/main.ts
+++ b/sendonly/main.ts
@@ -11,7 +11,7 @@ document.addEventListener("DOMContentLoaded", async () => {
   const signalingUrl = import.meta.env.VITE_SORA_SIGNALING_URL;
   const channelIdPrefix = import.meta.env.VITE_SORA_CHANNEL_ID_PREFIX || "";
   const channelIdSuffix = import.meta.env.VITE_SORA_CHANNEL_ID_SUFFIX || "";
-  const secretKey = import.meta.env.VITE_SORA_SECRET_KEY || "";
+  const secretKey = import.meta.env.VITE_SECRET_KEY || "";
 
   const client = new SoraClient(
     signalingUrl,
diff --git a/sendrecv/main.ts b/sendrecv/main.ts
index 5a8dff3..8a2208f 100644
--- a/sendrecv/main.ts
+++ b/sendrecv/main.ts
@@ -21,7 +21,7 @@ document.addEventListener("DOMContentLoaded", async () => {
   const signalingUrl = import.meta.env.VITE_SORA_SIGNALING_URL;
   const channelIdPrefix = import.meta.env.VITE_SORA_CHANNEL_ID_PREFIX || "";
   const channelIdSuffix = import.meta.env.VITE_SORA_CHANNEL_ID_SUFFIX || "";
-  const secretKey = import.meta.env.VITE_SORA_SECRET_KEY || "";
+  const secretKey = import.meta.env.VITE_SECRET_KEY || "";
 
   const client = new SoraClient(
     signalingUrl,
diff --git a/src/misc.ts b/src/misc.ts
index 4ea13e6..c507291 100644
--- a/src/misc.ts
+++ b/src/misc.ts
@@ -1,17 +1,20 @@
-import jose from "jose";
+import * as jose from "jose";
 
 export const generateJwt = async (
   channelId: string,
   secretKey: string,
 ): Promise<string> => {
+  if (secretKey === "") {
+    return "";
+  }
   const header = { alg: "HS256", typ: "JWT" };
-  const payload = {
-    // 30 秒後に有効期限切れ
-    exp: Math.floor(Date.now() / 1000) + 30,
-    channel_id: channelId,
-  };
-  return await new jose.SignJWT(payload)
-    .setProtectedHeader(header)
-    .setIssuedAt()
-    .sign(new TextEncoder().encode(secretKey));
+  return (
+    new jose.SignJWT({
+      channel_id: channelId,
+    })
+      .setProtectedHeader(header)
+      // 30 秒後に有効期限切れ
+      .setExpirationTime("30s")
+      .sign(new TextEncoder().encode(secretKey))
+  );
 };