No such file or directory and can't install library because it already exist.

When I try to install the library it says it already exist.
When I include the library in the code it says No such file or directory…

Library: https://github.com/adafruit/RTClib/blob/master/examples/timestamp/timestamp.ino

Code: #include <RTClib.h>

When try to install the library error:
“A library named RTClibmaster already exists”

When I try to validate the code :

arduino:4:10: fatal error: RTClib.h: No such file or directory

#include <RTClib.h>

^~~~~~~~~~

compilation terminated.

Multiple libraries were found for “SoftwareSerial.h”
Used: C:\Program Files (x86)\Arduino\hardware\arduino\avr\libraries\SoftwareSerial
Not used: C:\Users\user\Documents\Arduino\libraries\EspSoftwareSerial
exit status 1
RTClib.h: No such file or directory

please help

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