diff --git a/README.md b/README.md
index dd89b79..3fc9ad2 100644
--- a/README.md
+++ b/README.md
@@ -63,6 +63,8 @@ wget https://github.com/mirrors2/opencatd-open/raw/main/docker/docker-compose.ym
   - [Fly.io](https://fly.io/)
   - 或者其他
 
+修改openai的endpoint地址？使用任意上游地址(套娃代理)
+  - 设置环境变量 openai_endpoint
 # License
 
 [GNU General Public License v3.0](License)
\ No newline at end of file
diff --git a/router/router.go b/router/router.go
index 7f0e132..af58cf4 100644
--- a/router/router.go
+++ b/router/router.go
@@ -93,7 +93,7 @@ type ChatCompletionResponse struct {
 
 func init() {
 	if openai_endpoint := os.Getenv("openai_endpoint"); openai_endpoint != "" {
-		log.Println("replace %s to %s", baseUrl, openai_endpoint)
+		log.Println(fmt.Sprintf("replace %s to %s", baseUrl, openai_endpoint))
 		baseUrl = openai_endpoint
 	}
 }