It's easy to add GitHub buttons to webpages as a way to link to your profile. Is there an analogous button for Bitbucket accounts?
The short answer is not exactly.
It highly depends on what you want you want to do. If you need the current numbers like shown in https://ghbtns.com/ or you want the current user to create a fork without being redirected to Bitbucket website, you could send a POST request like explained in the fork api reference.
If you just want a button that looks and works approximately the same that you linked to, just place a normal bootstrap button and link it to your Bitbucket repo. For example if you want the "fork" link, get it by right clicking on "Fork this repository" menu item shown below and selecting "Copy link location/address". .
After the button works you'll probably want to style the button and the icon to look similar to a GitHub button. Note that Bitbucket has no "Star" function like GitHub.