Please provide steps to try running "ProveIt".

click on ਪਸੰਦਾਂ, then click on ਗੈਜਟ
then select ਹਵਾਲੇ ਜੋੜਨੇ ਆਸਾਨ ਬਣਾਉਂਦਾ ਹੈ।
then save by clicking on ਸੰਭਾਲੋ

General note: Bugzilla is NOT a place to report problems in local gadgets on some wikis and their configuration, so this report might end up as INVALID for Bugzilla if there is no problem with the *MediaWiki* software behind.

So this is not about http://proveit.wmflabs.org but about the gadget "ਹਵਾਲੇ ਜੋੜਨੇ ਆਸਾਨ ਬਣਾਉਂਦਾ ਹੈ।" listed under https://pa.wikipedia.org/wiki/ਖ਼ਾਸ:ਪਸੰਦਾਂ#mw-prefsection-gadgets . Alright. :)

(In reply to Satdeep Gill from comment #2)

click on ਪਸੰਦਾਂ, then click on ਗੈਜਟ
then select ਹਵਾਲੇ ਜੋੜਨੇ ਆਸਾਨ ਬਣਾਉਂਦਾ ਹੈ।
then save by clicking on ਸੰਭਾਲੋ

I did that and I get "ਤੁਹਾਡੀਆਂ ਪਸੰਦਾਂ ਸਾਂਭੀਆਂ ਗਈਆਂ ਹੈ।". What is "not working" here?

Please read https://www.mediawiki.org/wiki/How_to_report_a_bug - this report is currently too vague. A bug report should have clear steps so anybody else could try to reproduce the problem without wondering about the steps.

Also, did it work before on pa.wikipedia.org ? If so, when did it break? If ProveIt is something new on pa.wikipedia, did you follow https://en.wikipedia.org/wiki/User:ProveIt_GT#Non-English_Wikipedia ?

So https://en.wikipedia.org/wiki/User:ProveIt_GT#User_guide.2C_tutorial.2C_help links to http://proveit.wmflabs.org/users/bugreport which explains how to file bug reports, and that the developers do not use this Bugzilla but https://code.google.com/p/proveit-js/

Hence closing as INVALID as the problem itself might be valid, but the application is simply not handled in this Bugzilla.

Also, for your interest:
https://en.wikipedia.org/wiki/User_talk:ProveIt_GT#Not_working_in_Tamil_wikipedia
https://en.wikipedia.org/wiki/User_talk:ProveIt_GT#Punjabi_Wikipedia

The problem is that after saving the option. When i open any article i dont get the proveit toolbar under the page.

This should be part of the *complete* steps to reproduce the problem in a bug report on https://code.google.com/p/proveit-js/