# 💡Summary > [!Info] > 如果你不留电话（不配置回调 URL），银行审批完了也没法通知你 —— 你的 App 就永远不知道用户登录成功了。 > 因为箭头是反着的，是是从右往左的，所以得名回调 ![CleanShot 2026-01-24 at [email protected]|1000](https://imagehosting4picgo.oss-cn-beijing.aliyuncs.com/imagehosting/fix-dir%2Fmedia%2Fmedia_QZ2icS0B6X%2F2026%2F01%2F24%2F18-43-40-875883ce906d7bcb4b898f9dc53bd976-CleanShot%202026-01-24%20at%2018.43.30-2x-dcd7d1.png) # 🧩 Cues # 🪞Notes ![CleanShot 2026-01-24 at [email protected]|1000](https://imagehosting4picgo.oss-cn-beijing.aliyuncs.com/imagehosting/fix-dir%2Fmedia%2Fmedia_pVsvAvTKVZ%2F2026%2F01%2F24%2F18-43-26-c90006aa91535db4d034bc87fb007971-CleanShot%202026-01-24%20at%2018.43.14-2x-05419f.png) ![CleanShot 2026-01-24 at [email protected]|1000](https://imagehosting4picgo.oss-cn-beijing.aliyuncs.com/imagehosting/fix-dir%2Fmedia%2Fmedia_DlF5pFjsUx%2F2026%2F01%2F24%2F18-45-30-f505bccb09a617e091786fc3a75c1f3b-CleanShot%202026-01-24%20at%2018.45.22-2x-9412c4.png)