# Use balance to purchase
```javascript
WXAPI.cardBuy(token, id)
```
+ token current user login credentials
+ id membership card id
```json
{
"code": 0,
"msg": "success"
}
```
# Pay online for purchase
["Use of nextAction"](https://www.yuque.com/apifm/doc/aetmlb)
Just pass the following data to the nextAction parameter of the payment interface:
```json
{type:10, id:1234}
```
+ type is fixed at 10
+ id is the ID of the membership card