Enabling MySQL
Navigate to the configuration file: ch_cryptocurrencies/lua/ch_cryptocurrencies/shared/ch_cryptocurrencies_config.lua
On line 27 you change the CH_CryptoCurrencies.Config.EnableSQL configuration to true
Now on the next line you select the SQL module you wish to use. Garry's Mod has SQLite by default or you can use MySQLOO if you want.
I recommend MySQLOO
Then go to ch_cryptocurrencies/lua/ch_cryptocurrencies/server/mysql/mysql_connect.lua and type in your SQL credentials.
YOU NEED THE MYSQLOO MODULE IF YOU CHOOSE THAT
Get it here: https://github.com/FredyH/MySQLOO
Download the latest module for your server's operating system and architecture using the links provided on GitHub, then place that file within the garrysmod/lua/bin/ folder on your server. If the bin folder doesn't exist, please create it.