Anbox doesn't come pre-installed with Google Play Store and there's not even a package installer, so the only way to install applications in Anbozx is through Android Debug Bridge, aka ADB.
adb install /path/to/file.apk
adb install /home/sumeet/Downloads/opera.apk
* daemon not running. starting it now on port 5037 *
* daemon started successfully *
30103 KB/s (4597754 bytes in 0.149s)
Failure [INSTALL_FAILED_NO_MATCHING_ABIS: Failed to extract native libraries, res=-113]
Is this an Anbox problem, an Ubuntu problem or an ADB problem that can be fixed? Since Anbox is essentially just an Android emulator running on top of Linux, how can I fix this?