When not playing the game, disable the controller configuration by going to the notification area, right-clicking the antimicro icon, hovering over the controller and unchecking the Streets of Rage Remake configuration.
Now, map the rest of the controller to the corresponding keyboard keys shown in the game's options menu.
Make sure both the left and right buttons are set to the same button if they are not, the buttons will not work properly.
Click "L Trigger" and "R Trigger", and click both the left and right buttons to map it to the key that corresponds to the in-game keyboard key listed for the desired action.
If there are any problems, make sure there aren't any other XInput (Xbox/Xbox-like) controllers plugged in/activated, and make sure no other controller mapping software is running, including Steam Controller Support. It will be identified in antimicro as "XInput Controller".
Run antimicro, and select the tab that corresponds to the correct controller.
Set the game's controller settings to be 'Keyboard' and not 'Gamepad'.
If the controller isn't already in XInput mode, press and hold B+Start for 5 seconds to switch from DirectInput to XInput (The game may not recognize DirectInput signals from this controller).
Set the controller to XInput mode and use antimicro (or a similar program that allows mapping controller buttons to keyboard keypresses)