Google is complaining that it is not able to index hundreds of pages of my site.
Is my robot.txt is wrong? I’ve not changed anything (big) at all. yet this problem is there.
AI-generated summary
Bathinda is experiencing an issue where Google is unable to index hundreds of pages on their site, BathindaHelper.com. They have not made any significant changes and are unsure if their robot.txt file is the cause of the problem. Canapin suggested checking Google Search Console for clues, but Bathinda found that the suggested option Alternate page with proper canonical tag is no longer available. Bathinda is seeking guidance or resources to resolve the issue.
Hello Bathinda 
I don’t know much about SEO.
In Google Search Console, if you click on Alternate page with proper canonical tag, it will list such pages and might give you a clue why you have so many pages that are (presumably legitimately?) not referenced.
What did you change?
Thank you so much.
But there is no longer any option named ’ Alternate page with proper canonical tag
Next, I’ve not changed anything. Had loaded/given ‘Robot.txt’ path to google search console according to some web article read somewhere. But no longer remember what process did I take.
If you’ve not got time to reply to these, kindly give me some link by reading which I could sort this out.
Thank you again.