Compile Error - Confused on how to correct

I have been trying to figure out why I cannot get a good compile. For sure I've
done something wrong, but it escapes me as to how to get a good compile as I have
gotten in the past. Running the latest copy of the IDE 1.8.10; tools>>Board set
to "Ardinuo/genuine UNO"; tools/programmer set to "Arduino as ISP". Have succesfully
compiled several of the examplies without errors.

Thanks for looking and helping.... appreciated
Henri Monnier - hcm@themonniers.com

Download sketch and library here:
http://www.themonniers.com/Arduino.rar
------------------ERROR MESSAGE----------------------- (empty lines deleted)
Arduino: 1.8.10 (Windows 10), Board: "Arduino/Genuino Uno"
mouseoleum_arduino:55:10: error: PWMServo.h: No such file or directory
#include <PWMServo.h> // see comments at the end of the sketch
^~~~~~~~~~~~
compilation terminated.
exit status 1
PWMServo.h: No such file or directory
This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

The compiler tells you that the library "PWMservo" is missing. So you have to install it with help of the IDE.

btw: Near nobody will fight with rar archives. If you are willing to show your program, insert it with the </> brackets.