Erorr while installing the php script

Any time I want to install the PHP scripts but am facing the error 403 Forbidden
nginx,

Please help

aaP_ngbaze100
Hello, this should be intercepted by CDN. I suggest you try again later

it's not linked with CDN , any time i want to install script its shown an errors

aaP_ngbaze100
Hello, our server uses CDN, is it normal now?

here the URL i want to install the script on it, https://allseolab.com