PHPMyAdmin error requested authentication method unknown to the client [caching_sha2_password]

Whilst trying to install or use PHPMyAdmin, you might encounter the following errors:

mysqli_real_connect(): The server requested authentication method unknown to the client [caching_sha2_password]
mysqli_real_connect(): (HY000/2054): The server requested authentication method unknown to the client

The reason why this happens is because of authentication method changes in later version of MySQL.

TL;DR

Change

# mysql -u root -pPASSWORD

First syntax (depends on version of MySQL):

mysql> ALTER USER 'user'@'localhost' IDENTIFIED WITH mysql_native_password BY 'user_password';

or

mysql> ALTER USER root IDENTIFIED WITH mysql_native_password BY 'PASSWORD';

There are other ways of doing this as well, so be sure to follow the reference below if you want the complete story.

Reference:
https://stackoverflow.com/questions/49948350/phpmyadmin-on-mysql-8-0