install version php 8 laravel 8 my error

[IBMBAROOEI]

Your requirements could not be resolved to an installable set of packages.

Problem 1
- spatie/laravel-backup[7.5.0, ..., 7.5.3] require ext-pcntl * -> it is missing from your system. Install or enable PHP's pcnt
l extension.
- Root composer.json requires spatie/laravel-backup ^7.5 -> satisfiable by spatie/laravel-backup[7.5.0, 7.5.1, 7.5.2, 7.5.3].

To enable extensions, verify that they are enabled in your .ini files:
- D:\lastversion php\php\php.ini
You can also run php --ini inside terminal to see which files are used by PHP in CLI mode.

Installation failed, reverting ./composer.json and ./composer.lock to their original content.