Iframe error explanation

explain me error in attached image iframe

Short version: the 3-D Secure (SCA) challenge that should load inside the checkout iframe isn’t loading.
The iframe is trying to open:

`https://www.rsa3dsauth.co.uk/3ds2/cReqWebBased?issuer=fis`

(An issuer/ACS page used for 3DS2.) Chrome can’t reach it, so it shows “The web page … might be temporarily down or moved.”

### What this usually means
– The ACS endpoint is temporarily down or unreachable from the user’s network (DNS/TLS/firewall/ad-block/VPN).
– Or your page’s security headers block the frame (e.g., `Content-Security-Policy` `frame-src`/`child-src` doesn’t include `https://www.rsa3dsauth.co.uk`), or the ACS rejects being framed for your origin.

### Quick checks
1. Open DevTools → **Network** and **Console**; reload and look for the iframe request:
– `net::ERR_NAME_NOT_RESOLVED`, `ERR_CONNECTION_TIMED_OUT`, or `ERR_SSL_*` ⇒ network/TLS issue.
– “Refused to display … in a frame” or CSP violation ⇒ header/config issue.
2. Try opening that URL in a **new tab** (same device/network). If it fails there too, it’s an upstream/ network problem.
3. Disable ad-blockers/VPN; try on mobile data or another network.
4. Inspect your response headers for CSP: make sure `frame-src` (or `child-src`) allows
`https://www.rsa3dsauth.co.uk` (and any gateway domains).
5. If you’re using Global Payments/Realex:
– Provide them the timestamp, HPP/txn id, and card BIN to check ACS availability.
– As a workaround, switch the 3DS challenge to **full-page/redirect** instead of embedded iframe.

Bottom line: it’s not a card/amount error; it’s the external 3DS page failing to load in the iframe—either unreachable or blocked by framing/security settings.

​I've debuged the issue here are my finding are
​Maybe payment server "www.rsa3dsauth.co.uk" down
​page’s security headers block the frame url above
​or it may be server glitch temproratly
Correct above sentence

​I've debuged the issue here are my finding are
​Maybe payment server "www.rsa3dsauth.co.uk" down
​page’s security headers block the frame url above
​or it may be server glitch temproratly
Correct above sentence

Here’s a clean version:

“I’ve debugged the issue. My findings are:
1) The payment server (www.rsa3dsauth.co.uk) may be down;
2) The page’s security headers might be blocking the iframe URL; or
3) It could be a temporary server glitch.”