out of memory error when require-ing mercure

I'm trying to install mercure(https://symfony.com/doc/current/mercure.html). I am getting this error.

This be the command I used:

composer require symfony/mercure

I even tried this:

php -d memory_limit=-1 composer.phar require symfony/mercure and I still get the same error.

The error message:

    $ composer require symfony/mercure
PHP Warning: Module 'openssl' already loaded in Unknown on line 0

Warning: Module 'openssl' already loaded in Unknown on line 0
Using version ^0.1.0 for symfony/mercure
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)

VirtualAlloc() failed: [0x00000008] Not enough memory resources are available to process this command.

VirtualFree() failed: [0x000001e7] Attempt to access invalid address.

VirtualAlloc() failed: [0x00000008] Not enough memory resources are available to process this command.

VirtualFree() failed: [0x000001e7] Attempt to access invalid address.

PHP Fatal error: Out of memory (allocated 1570766848) (tried to allocate 4096 bytes) in phar://C:/ProgramData/ComposerSetup/bin/composer.phar/src/Composer/DependencyResolver/Solver.php on line 223

Fatal error: Out of memory (allocated 1570766848) (tried to allocate 4096 bytes) in phar://C:/ProgramData/ComposerSetup/bin/composer.phar/src/Composer/DependencyResolver/Solver.php on line 223