我正在尝试将我用普通PHP 7.2.1编写的应用程序推送到Heroku。我使用apache和mariaDB在本地docker容器中开发，一切正常。当我进入Heroku时，将加载索引页面，但是如果我尝试登录或进入任何其他页面，则没有任何效果，并且我得到一个空白页面。我使用clearDB附加组件，并仅通过CLI在其中导入了mariaDB .sql导出文件。该网站使用URL重写，路由器和.htaccess。
我在这里已经阅读了其他问题，看来问题可能来自多个角度。不幸的是，我是很多新手，我很难理解错误日志。我认为这些（或全部）中的任何一个都可能是错误的：
根据以下信息，我应该/应该如何对应用程序进行故障排除？
这是我的.htaccess：
RewriteEngine On
RewriteRule ^([a-zA-Z0-9-_/]*)$ index.php?id=$1 [QSA,L]
这是构建日志：
-----> PHP app detected
! WARNING: No 'composer.json' found!
! Your project only contains an 'index.php', no 'composer.json'.
! Using 'index.php' to declare app type as PHP is deprecated and
! may lead to unexpected behavior.
! Please consider updating your codebase to utilize Composer and
! modern dependency management in order to benefit from the latest
! PHP runtimes and improved application performance, as well as
! control over the PHP versions and extensions available.
! For an introduction to dependency management with Composer and
! how to get the most out of PHP on Heroku, refer to the docs at
! https://getcomposer.org/doc/00-intro.md and
! https://devcenter.heroku.com/articles/getting-started-with-php
-----> Bootstrapping...
-----> Installing platform packages...
NOTICE: No runtime required in composer.lock; using PHP ^7.0.0
- php (7.3.11)
- apache (2.4.41)
- nginx (1.16.1)
-----> Installing dependencies...
Composer version 1.9.0 2019-08-02 20:55:32
-----> Preparing runtime environment...
NOTICE: No Procfile, using 'web: heroku-php-apache2'.
-----> Checking for additional extensions to install...
-----> Discovering process types
Procfile declares types -> web
-----> Compressing...
Done: 18.5M
-----> Launching...
Released v5
https://cogip-becode.herokuapp.com/ deployed to Heroku
这是应用程序日志：
2019-11-08T12:59:03.464108+00:00 heroku[router]: at=info method=GET path="/assets/css/style.css" host=cogip-becode.herokuapp.com request_id=527c0174-09a9-42c9-9a08-4253b4baa78d fwd="84.198.194.106" dyno=web.1 connect=1ms service=1ms status=304 bytes=128 protocol=https
2019-11-08T12:59:08.532874+00:00 heroku[router]: at=info method=POST path="/" host=cogip-becode.herokuapp.com request_id=d7eea251-3d27-49c5-bd54-75d9583b3dd4 fwd="84.198.194.106" dyno=web.1 connect=1ms service=3ms status=500 bytes=279 protocol=https
2019-11-08T12:59:08.533394+00:00 app[web.1]: [08-Nov-2019 12:59:08 UTC] PHP Notice: Undefined index: id in /app/index.php on line 4
2019-11-08T12:59:08.533891+00:00 app[web.1]: [08-Nov-2019 12:59:08 UTC] PHP Parse error: syntax error, unexpected 'cleardb' (T_STRING) in /app/database/connection.php on line 3
2019-11-08T12:59:08.534564+00:00 app[web.1]: 10.11.238.43 - - [08/Nov/2019:12:59:08 +0000] "POST / HTTP/1.1" 500 - "https://cogip-becode.herokuapp.com/" "Mozilla/5.0 (X11; Linux x86_64; rv:60.9) Gecko/20100101 Goanna/4.4 Firefox/60.9 PaleMoon/28.7.1