update readme md

dipudey · dipudey · commit 61105ffa0f6f · 2022-09-01T16:40:32.000+06:00
diff --git a/README.md b/README.md
@@ -55,6 +55,7 @@ UPAY_MERCHANT_CODE=""
 UPAY_MERCHANT_NAME=""
 UPAY_MERCHANT_MOBILE=""
 UPAY_MERCHANT_CITY=""
+UPAY_CATEGORY_CODE=""
 UPAY_CALLBACK_URL=""
 ```
 
