[Vuejs]-V-autocomplete how to detect if no result and add custom action

Try adding v-if directive in v-row. I assume that usersData is an array:

<v-row v-if="usersData.length == 0">
  <v-col cols="8">
    <v-row>
      <v-subheader>
        Can’t find who you’re looking for?
      </v-subheader>
    </v-row>

    <v-btn>
      <v-icon>
        mdi-plus
      </v-icon>
      Add new speaker
    </v-btn>
  </v-col>
</v-row>