updated as per the review comments

pkg/plugin/implementation/reqpreprocessor/cmd/plugin.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"context"
+	"net/http"
+	"strings"
+
+	"github.com/beckn/beckn-onix/pkg/plugin/implementation/reqpreprocessor"
+)
+
+type provider struct{}
+
+func (p provider) New(ctx context.Context, c map[string]string) (func(http.Handler) http.Handler, error) {
+	config := &reqpreprocessor.Config{}
+	if contextKeysStr, ok := c["contextKeys"]; ok {
+		config.ContextKeys = strings.Split(contextKeysStr, ",")
+	}
+	if role, ok := c["role"]; ok {
+		config.Role = role
+	}
+	return reqpreprocessor.NewPreProcessor(config)
+}
+
+var Provider = provider{}