Toast light prompt for using vant component library in Vue

Record the toast light prompt in vant today, and use it according to the methods in the official documents. It can’t be used if an error is found
this is what the document says

Toast.success('success');
Toast.fail('fail');

After referencing vant in main.js, directly call toast to report an error
the actual usage is as follows:

this.$toast.success("success");
this.$toast.fail("fail");

Like calling routing, you need to click this.