thinkphp5 url problem

Question

First there is a question about thinkphp5 url beautification. I set the configuration file 'url_param_type'=> 1, and the generated route is http://www.art-school.com/about/index/1. html Redefine routing rules 'about/index/[:pid]' => ['index/about/index', ['method' => 'get'], ['pid' => ' \d{4}']], But when printing the received get value in the method, it is empty. What is the reason? If the get value can be printed