How to install GD on Heroku
I run composer require ext-gd and git push heroku master it did work.
I tried add "gd": "*" to composer.json and perform composer update but when push to Heroku meet error with Class 'Symfony\Component\HttpFoundation\InputBag' not found. I think it's not only update ext-gd with composer update
In composer.json file
"require": { "facade/ignition": "^2.3.6", "fzaninotto/faker": "^1.9.1", "mockery/mockery": "^1.3.1", "nunomaduro/collision": "^5.0", "phpunit/phpunit": "^9.3", "ext-gd": "*" },Update composer and push to origin branch
composer updategit add .git commit -m "message"git push origin <branch name>Rebuild your project at Heroku
https://devcenter.heroku.com/articles/php-support#extensions