How they are doing this? With which plugin?

hi

When you select a package from smm sites they are asking your instagram username and when you write you username they are showing your profile picture follower count etc.I am trying to find out how they are doing this for hours but no luck

https://www.idigic.net/checkout/?package=8https://buzzoid.com/order/select/112?variant=
etc..you can find more examples if you write google "buy instagram followers" almost all have this option..

You will need to use Instagram API . More info
https://stackoverflow.com/questions/50086945/how-to-get-instagram-profile-picture

they use instagram api.
Ask a developer to help you with api integration.

thanks all for the answers