herokuのアップロードでつまずいている。

Question

開発環境
php バージョン＝PHP 7.3.29
laravelバージョン＝laravel5.8
MAMP
vscode

herokuのアップロードで、

heroku run php artisan migrate

を実行した時に、

bash: php: command not found

とエラーが表示されます。

その前の作業で怪しい点は、

git push heroku main 

コマンドを実行した時に、

〜省略〜
remote:  !     WARNING: Your app's PHP version is no longer actively maintained
remote:  !     
remote:  !     Only security updates will be provided for your PHP version
remote:  !     series by the PHP Group until its end-of-life on 2022-11-28.
remote:  !     
remote:  !     It is strongly recommended you update your app to a version of
remote:  !     PHP with "active support" status immediately to ensure you get
remote:  !     the latest bugfixes and security updates each time you deploy.
remote:  !     
remote:  !     You may check the list of versions supported by the PHP Group
remote:  !     and their EOL dates here: http://php.net/supported-versions.php
remote:  !     
remote:  !     For a list of supported runtimes & extensions on Heroku, please
remote:  !     refer to: https://devcenter.heroku.com/articles/php-support
remote: 
〜省略〜
remote:  !     ERROR: Dependency installation failed!
remote:  !     
remote:  !     The 'composer install' process failed with an error. The cause
remote:  !     may be the download or installation of packages, or a pre- or
remote:  !     post-install hook (e.g. a 'post-install-cmd' item in 'scripts')
remote:  !     in your 'composer.json'.
remote:  !     
remote:  !     Typical error cases are out-of-date or missing parts of code,
remote:  !     timeouts when making external connections, or memory limits.
remote:  !     
remote:  !     Check the above error output closely to determine the cause of
remote:  !     the problem, ensure the code you're pushing is functioning
remote:  !     properly, and that all local changes are committed correctly.
remote:  !     
remote:  !     For more information on builds for PHP on Heroku, refer to
remote:  !     https://devcenter.heroku.com/articles/php-support
remote:  !     
remote:  !     REMINDER: the following warnings were emitted during the build;
remote:  !     check the details above, as they may be related to this error:
remote:  !     - Your app's PHP version is no longer actively maintained
remote: 
〜省略〜

とエラーが表示された事です。

また、

heroku apps:info

コマンドを実行した時には、ブラウザに

Heroku | Welcome to your new app!
Refer to the documentation if you need help deploying.

と表示されています。

ご回答の程宜しくお願いいたします。