How to use Viettel CDN for Website in VietNam

How to use Viettel CDN for Website in VietNam

VIETTEL provided this CDN without any document or direction
A/ Import SSL CERT for domain or subdomain you want to push content to VIETTEL CDN
B/ Config domain or subdomain to CDN
#THE-END
P.S: They seem to use OpenResty for their "CDN". I don't think so this is really CDN like Akamai Technologies, , CloudFlare,...

[x]CDN Services -> Setting -> SSL
1/ SSLNAME: <domain or subdomain>
ex: img.example.com
2/ SSL CERT (.crt): fullchain.pem.crt
3/ SSL KEY (.key): privkey.pem.key
4/ SSL Description: Type what you want
5/ SAVE 


CDN Services -> Web Accelerator -> "Add new WEB CDN"
1/ CDN Name: Domain or subdomain want to push content to VIETTEL CDN
2/ CDN CName: Domain or subdomain want to push content to VIETTEL CDN 
3/ CDN Description: Type what you want
4/ CDN Domain Host:
4.1/ any keyword what you want. ex: abc
4.2/ subdomain auto-generated by VIETTEL CDN. ex: web.4656460e.viettel-cdn.vn
-->This field is CNAME Value on your Domain DNS RECORD. ex:
img -> abc.web.4656460e.viettel-cdn.vn
5/ Cache Popular Resources:
[x] Images (jpg,jpeg,png,gif)
6/ Available Origins: point to IP HOST that contain your static content
7/ SSL Option: 
(x) HTTPS
8/ SSL CERT: ref A.1
9/ CDN Status: 
(x) Active CDN: if you want to ACTIVE this CDN CONTENT
(x) Inactive CDN: If you want to DISABLE this CDN CONTENT