[Vuejs]-How do you set the default value for multiple selects on a page with vuetify?

As I understand it you want the v-model to run for each row. This is easy to do, but you need to create an array beforehand. You can then assign default values for this array.

Check it. https://codesandbox.io/p/github/eguvenc/test/

<template>
  <v-container>
    <v-row>
      <v-col cols="6">

      <VDataTable
        v-model:expanded="expanded"
        :items-per-page="5"
        :headers="headers"
        :items="requests"
        item-value="id"
        class="elevation-1"
        show-expand
        :loading="loading"
    >
        <template v-slot:top>
            <VToolbar flat>
                <v-toolbar-title>Estimate Requests</v-toolbar-title>
            </VToolbar>
        </template>
        <template #item.customer_name="{ item }"> {{ item.raw.customer.fname }} {{ item.raw.customer.lname }} </template>
        <template #item.status="{ item }">
            <v-select
              v-model="form[item.index].status"
              :items="statuses"
            />
        </template>
        <template v-slot:expanded-row="{ columns, item }">
            <tr>
                <td :colspan="columns.length">
                    <address>{{item.raw.address}}<br />{{item.raw.city}}, {{item.raw.state}} {{item.raw.zip}}</address>
                </td>
            </tr>
        </template>
    </VDataTable>

      </v-col>
    </v-row>
  </v-container>
</template>

<script>
export default {
  components: {
    
  },
  data () {
    return {
        form: [
          { status: 1 },
          { status: 2 }
        ],
        statuses: [1, 2],
        requests: [
          { id: 1, name: "James Brown", email: "jb@example.com" },
          { id: 2, name: "Eli Brown", email: "eli@example.com" }
        ],
        expanded:[],
        headers: [
            { title: 'ID', align: 'start', key: 'id' },
            { title: 'Name', align: 'start', key: 'name' },
            { title: 'Email', align: 'start', key: 'email' },
            { title: 'Status', align: 'start', key: 'status' },
        ]
    }
  },
  computed: {

  },
  created() {

  },
  methods: {
   
  }, // end methods
}
</script>