How to create a cmake interface library(header only library) and link it in another project

Interface library printer contains three files CMakeLists.txt, print.hpp and print.inl

CMakeLists.txt

cmake_minimum_required(VERSION 3.0.0)
project(printer VERSION 0.1.0)

include(CTest)
enable_testing()

add_library(printer INTERFACE print.hpp print.inl)

set_target_properties(printer PROPERTIES CXX_STANDARD 20)
set_target_properties(printer PROPERTIES LINKER_LANGUAGE CXX)

set(CPACK_PROJECT_NAME ${PROJECT_NAME})
set(CPACK_PROJECT_VERSION ${PROJECT_VERSION})
include(CPack)

print.hpp

#ifndef PRINT_H
#define PRINT_H

template<typename T>
void print(const T& t);

#include "print.inl"

#endif

print.inl

#include <iostream>

template<typename T>
void print(const T& t) {
   std::cout << t << std::endl;
}

Print_App project includes the above interface library

CMakeLists.txt

cmake_minimum_required(VERSION 3.0.0)
project(print_app VERSION 0.1.0 LANGUAGES CXX)

include(CTest)
enable_testing()

add_executable(print_app
   main.cpp
)

set_target_properties(print_app PROPERTIES CXX_STANDARD 20)
target_link_libraries(print_app INTERFACE printer)

set(CPACK_PROJECT_NAME ${PROJECT_NAME})
set(CPACK_PROJECT_VERSION ${PROJECT_VERSION})
include(CPack)

main.cpp

#include <iostream>

// how to include the below header file without specifying the relative path like below
// #include "print.hpp"
#include "../stlib/print.hpp"

int main() {
   std::cout << "Hello, world!" << std::endl;

   print(10);
   print("abc");
   print(1.23456789);
}

In the Makefile of print_app, I see no mention of printer library.