Once you inject mirror,
1- go to the colour tab
2- Type a cfg name in the " [ _ ] " space on the middle right.
3- Click "add config"
A CFG File will have apeared in the CSGO folder.
The location should be: C:\Steam\steamapps\common\Counter-Strike Global Offensive\miroawr\cfg
To add a cfg, you can:
A- Open the one already there, and replace the inside of the file by deleting
the whole thing, then pasting the text from the included cfg into it, then save.
or
B- Place the desired cfg in the file. Then, open the .TXT called "miroawr_configs,
and type the cfg name 1 line below the last saved cfg, like this
https://gyazo.com/9a2948c43e34b044953151c63f60ab2e