update

README.md

@@ -7,7 +7,7 @@
 [![Github](https://img.shields.io/github/followers/iGoogle-ink?label=Follow&style=social)](https://github.com/iGoogle-ink)
 [![Github](https://img.shields.io/github/forks/go-pay/gopay?label=Fork&style=social)](https://github.com/go-pay/gopay/fork)
 
-[![Golang](https://img.shields.io/badge/golang-1.20-brightgreen.svg)](https://golang.google.cn)
+[![Golang](https://img.shields.io/badge/golang-1.21-brightgreen.svg)](https://golang.google.cn)
 [![GoDoc](https://img.shields.io/badge/doc-pkg.go.dev-informational.svg)](https://pkg.go.dev/github.com/go-pay/gopay)
 [![Go](https://github.com/go-pay/gopay/actions/workflows/go.yml/badge.svg)](https://github.com/go-pay/gopay/actions/workflows/go.yml)
 [![GitHub Release](https://img.shields.io/github/v/release/go-pay/gopay)](https://github.com/go-pay/gopay/releases)