Install APK from ADB and bypassing the prompt on Redmi Device = Redmi 5 Plus.

I have 250 apps as a .bak created by PC app. But the cheater PC app is asking for premium to restore it now. So, I can extract the .bak and find my apps.

I wanted to batch install those apks. I tried adb install apkname.apk to check if it works. But the phone keeps prompting me to accept the install and countdown starts, or else it will auto deny after countdown finishes. I've also tried 3rd-party app like ApkInstaller but it's the same.

I read many articles and they say it works without prompt. So, why am I getting this issue? How to bypass this prompt automatically?
In addition to adb install, you can directly use package manager from adb shell to install apps. Place .apk files in /data/local/tmp and make sure files are readable, SELinux context must be u:object_r:shell_data_file:s0. Now:

~$ cd /data/local/tmp
~$ ls *.apk | xargs -I {} pm install '{}'


Another simple root solution is to use some file explorer e.g. MiXplorer to batch install apps. Select all .apk files and tap on Install from menu.