Can I change the purpose of the Buzzer pin?

I have the new version of the Flywoo Goku F745 AIO. For whatever reason, the new version got rid of the motor 5-8 pins. I need at least one for a PWM out. I want to reuse the buzzer pin (BB-) as a PWM out (since we don’t use the buzzer) Looking in the firmware it looks like it is set up as GPIO? How to I change this to be a PWM?

# Buzzer - DMA timer channel use by LEDs
#PD15 TIM4_CH4 TIM4 GPIO(80) ALARM
PD15 BUZZER OUTPUT GPIO(80) LOW
define HAL_BUZZER_PIN 80
define HAL_BUZZER_ON 1
define HAL_BUZZER_OFF 0