How to make TELEGRAM to Join compulsory to access the website’s page?

Hello Members,
I have a little feature which I want to add in my website.

I want that if somebody opens any page of my website, A popup message of “You have to Join the TELEGRAM Channel first” should come & if the users want to access the page, they have to join the TeleGram Channel Compulsory through the given link. Without joining the Telegram channel, the page should not be accessible.
Is it possible!! Can we add some type of feature like this??

if anyone help [It would be helpful].
Thank You.

I added the POPUP saying ‘Join the Telegram Channel first’ but It didn’t work. As it was happening that if the user click the Join Button and then came back without joining it, the page was becoming accessible, which I don’t want.
[ USER HAVE TO JOIN THE TELEGRAM CHANNEL COMPULSORY ]