很简单，把 <button open-type="agreePrivacyAuthorization" /> 做成登录页中常见并且需要勾选的【已阅读并同意《用户协议》、《隐私协议》】的那个radio就行了

<template>
  <view>
    <view class="flex"><text>手机号</text><text>18612341234</text></view>
    <view class="flex"><text>短信验证码</text><text>1234</text></view>
    <button v-if="!isChecked" @click="handlegetPhonenumberFake">获取手机号（假）</button>
    <button v-else open-type="getPhoneNumber" @getphonenumber="handlegetPhonenumber"> 获取手机号（真）</button>
    <view class="flex">
      <button
        class="radio"
        :class="{ current: isChecked }"
        open-type="agreePrivacyAuthorization"
        @click="handleClick"
      />
      已阅读并同意《隐私协议》、《用户协议》
    </view>
    <button @click="handleLogin">登录</button>
  </view>
</template>
<script>
export default {
  data() {
    return { isChecked: false };
  },
  mounted() {},
  methods: {
    handlegetPhonenumberFake() {
      uni.showToast({
        title: '请先阅读并勾选隐私协议、用户协议',
        icon: 'none',
        duration: 2000,
      });
    },
    handlegetPhonenumber(event) {
      if (this.isChecked) {
        const { iv, code } = event.detail;
        console.log('iv', iv);
        console.log('code', code);
      } else {
        uni.showToast({
          title: '请先阅读并勾选隐私协议、用户协议',
          icon: 'none',
          duration: 2000,
        });
      }
    },
    handleClick() {
      this.isChecked = !this.isChecked;
    },
    handleLogin() {
      if (this.isChecked) {
        // 登录业务代码...

        // 登录成功后返回页面
        uni.navigateBack();
      } else {
        uni.showToast({
          title: '请先阅读并勾选隐私协议、用户协议',
          icon: 'none',
          duration: 2000,
        });
      }
    },
  },
};