This is the wiki page for the console command:
The bind command allows binding console commands to keyboard, mouse, or controller keys.
To use the command, open the console and type:
bind A "sv_soccar_gamespeed 2"
This will bind the command "sv_soccar_gamespeed 2" to the button A on the keyboard. (The button may vary based on keyboard layout) To figure out the correct name of any key, you can set
which will write the name of any keypress into the console window. Alternatively, you can set up bindings through the GUI.
Any change of the BakkesMod configuration made through the console is temporary and will be lost when you close Rocket League unless you open and close the GUI once or call the command
Toggle-able Binds Edit
There also exists the ability to toggle between different values with a single bind using the toggle syntax.
bind A "toggle sv_soccar_gamespeed 0.66 1 2";
The above command will set the game speed to 0.66 on press #1, 1.0 on press #2, 2.0 on press #3, and then repeats the pattern indefinitely. Simply use the writeconfig command in order to save this to your binds and have it persist.