Issue
A required package was not found Call Stack (most recent call first): /snap/flutter/101/usr/share/cmake-3.10/Modules/FindPkgConfig.cmake:597 (_pkg_check_modules_internal) flutter/ephemeral/.plugin_symlinks/flutter_secure_storage/linux/CMakeLists.txt:14 (pkg_check_modules)
Solution
In the doc of the package you can see it needs libsecret.
You just need to install the following packages:
sudo apt install libsecret-1-dev libsecret-tools libsecret-1-0
That worked for me :)
Answered By - A.Wy Answer Checked By - Marie Seifert (WPSolving Admin)