403 problem is displayed on the management page of tomcat8 or above

Modify conf/tomcat-users.xml

<role rolename="manager"/>
<role rolename="manager-gui"/>
<role rolename="admin"/>
<user username="user" password="password" roles="admin,manager,manager-gui"/>

It also needs to be modified. If there is no new conf/Catalina/localhost/manager.xml, the content is as follows:

<Context privileged="true" antiResourceLocking="false"
         docBase="${catalina.home}/webapps/manager">
    <Valve className="org.apache.catalina.valves.RemoteAddrValve" allow="^.*$" />
</Context>

It takes effect without restarting tomcat.