You can see Instruction details on PNR forum main page..
/pnr
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To POST/REFRESH PNRs, click here, and Copy/Paste the text to your Browser Bookmarks.
Bookmark Name=PNR Refresh.
Bookmark...
more... Link=(text seen below)
Instructions to Post/Refresh PNRs
1. Add the above text as a bookmark to your browser.
2. Enter PNR Number/Post PNR/Refresh PNR Status in IRI. This will take you to the Official Site.
3. Click on the 'PNR Refresh' bookmark. This will pre-fill the PNR Number.
4. Click Submit, Fill Captcha & Submit again. Now, you see the Official PNR Results page.
5. Click the "PNR Refresh" bookmark to post PNR to IRI.
Thanks for your patience during this hardship.
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Just follow it you will get to know, this isn't a thing only in IRI all PNR prediction sites, due to restriction enforced from Official site end.