qimall/addons/Store/backend/views/setting/store.php

<el-row>
    <el-col :span="24">
        <div class="form-body">
            <el-form :model="basicForm" ref="storeForm" :rules="storeFormRules" label-width="172px" style="position: relative" size="small">
                <el-form-item label="商家地址：">
                    <el-input type="text" size="small" v-model="storeForm.store_h5_login_url">
                        <el-button slot="append" @click="copyStoreLink(storeForm.store_h5_login_url)">复制链接</el-button>
                    </el-input>
                </el-form-item>

            </el-form>
        </div>
    </el-col>
</el-row>
<!-- 这个是复制用的容器，已隐藏 -->
<textarea style="opacity: 0;width: 0;height: 0;" id="copy-container-store"></textarea>