PWM frequency library

Thanks for your reply runnerup, although I will have to call for your help once again as I am new to Arduino but the deadline for my project is fast approaching!! I am trying my best but am still getting compile errors, so I was hoping you could take a look at the source code I have written and with the knowledge that I am using an Arduino Uno and possibly you could spot what is going wrong!

 # include "PWM.h" 

//Initialize Motor 1
int InA1 = 8;
int InB1 = 12;
int PWM1 = 10;
int32_t frequency = 20000;

void setup() 

{  
  
   InitTimersSafe();
   bool success = SetPinFrequencySafe(PWM1, frequency);
  
   if(success){
   pinMode (InA1, OUTPUT);
   pinMode (InB1, OUTPUT);
   pinMode (PWM1, OUTPUT);}
 
}
 
void loop ()
{
  
  
  {//Motor Start Delay
       delay(1000);
       
   //Motor Direction
       digitalWrite(InA1, HIGH);
       digitalWrite(InB1, LOW); }
     
   
   //Motor Acceleration Control
       {for(int fadeValue = 0 ; fadeValue <= 76; fadeValue +=5){
         pwmWrite(PWM1, fadeValue);
       
         delay(100000); }
       }
       
   //Motor Run Time        
       delay(10000);
       
   //Motor Decceleration Control
       {for(int fadeValue = 76; fadeValue >= 0; fadeValue -=5){
          pwmWrite(PWM1, fadeValue);
          
          delay(100000); 
       }
       }  
         
   //Motor Stop Time
       delay(10000); 
  
}

Here is the error I am now getting. I have installed v4.0.

Many thanks!