Can not remote access Mac XAMPP

[flyker]

I have setup the localhost base on XAMPP, and all the devices can access it in the local network. But I can not access the XAMPP from outside public ip.
I have change the listen port to 8080
I have change the httpd-xampp.conf:
<Directory "/Applications/XAMPP/xamppfiles/phpmyadmin">
AllowOverride AuthConfig Limit
Require all granted
ErrorDocument 403 /error/XAMPP_FORBIDDEN.html.var
</Directory>
I have set the forward port in router
My location is China, but I have the pulic IP and I use the DDNS.

Does anyone know how to do it? Thanks