vue project this. $router. go (- 1) can't goback

In the Vue project, hash route 'this. $router. go (- 1)' is used, and click button the url '#' before has a '?' & Causes the previous page to fail , double click It will take effect but url err

this origin url

http://localhost/payment/#/certification/detail

if i click goback the url change

http://localhost/payment/?#/certification/detail

 my code 

//button
<button class="btn back p-cu-p" @click="goback">GoBack</button>

//function
goback () {

this.$router.go(-1)

},

//route
{

path: '/certification',
name: 'CertifictionIndex',
component: () => import('@/views/CustomerManagement/certificationIndex.vue'),
children: [
{
path: '/',
name: 'Certifiction',
component: () => import('@/views/CustomerManagement/certification.vue'),
},
{
path: 'detail',
name: 'CertifictionDetail',
component: () => import('@/views/CustomerManagement/certificationDetail.vue'),
},
],
}