When this problem occurs, the general php version is below 7.2, and overtrue/wechat removed the dependency of this package in a version that depends on a version below php7.2, causing this package to not be installed normally. The solution is as follows :
1. [Recommended method] Upgrade php to 7.2 or 7.3 (7.4 is not adapted, do not use), and then execute composer update (make sure that the command line php version and the execution code version are always)
2. Manually install the missing extension packages, the possible missing packages are as follows
composer require symfony/event-dispatcher=^4.3
composer require monolog/monolog=^1.22
composer require symfony/http-foundation=^3.0