Composer.json defines the dependency, but the composer was not found.

Question

I added sendgrid and changed the composer.json file in heroku. The composer.json file contains

{
    "require": {
        "ext-mbstring": "*",
        "sendgrid/sendgrid": "2.0.5"
    }
}

to fix the file

When I click on a hero, I see an error, as shown below.

Answer 1

After installing the composer and rebooting the computer, I used the command composer update, and then it works fine and the error is fixed

Answer 2

, php-, composer update --ignore-platform-reqs. , , .