Error with php artisan command

[mohamedmehdigara]

PHP Warning: require(C:\Users\Admin\Downloads\freeCodeGram/vendor/autoload.php): Failed to open stream: No such file or directory in C:\Users\Admin\Downloads\freeCodeGram\artisan on line 18
PHP Fatal error: Uncaught Error: Failed opening required 'C:\Users\Admin\Downloads\freeCodeGram/vendor/autoload.php' (include_path='.;C:\php\pear') in C:\Users\Admin\Downloads\freeCodeGram\artisan:18
Stack trace:
#0 {main}
thrown in C:\Users\Admin\Downloads\freeCodeGram\artisan on line 18

[TarcisioJuniorGT]

I need help with this too, please!

[iamroxified]

Warning: require(C:\Users\Roxified\Desktop\freecodegram/vendor/autoload.php): Failed to open stream: No such file or directory in C:\Users
Roxified\Desktop\freecodegram\artisan on line 18
PHP Fatal error: Uncaught Error: Failed opening required 'C:\Users\Roxified\Desktop\freecodegram/vendor/autoload.php' (include_path='C:\xa
mpp\php\PEAR') in C:\Users\Roxified\Desktop\freecodegram\artisan:18
Stack trace:
#0 {main}
thrown in C:\Users\Roxified\Desktop\freecodegram\artisan on line 18

Fatal error: Uncaught Error: Failed opening required 'C:\Users\Roxified\Desktop\freecodegram/vendor/autoload.php' (include_path='C:\xampp\p
hp\PEAR') in C:\Users\Roxified\Desktop\freecodegram\artisan:18
Stack trace:
#0 {main}
thrown in C:\Users\Roxified\Desktop\freecodegram\artisan on line 18