First find the makey that you want to embed. Go to that makey page and find the ID for that makey. You will find the ID for the makey in the URL link. A typical makey url link will be - http://www.makeystreet.com/makey/2976/. The ID is the number that comes after www.makeystreet.com/makey/. In this case the ID is 2976. 

In order to embed the makey on your wesbite, copy this embedded code and paste this on your website. 

<iframe src="//www.makeystreet.com/embed/makey/id/" width="250" height="430" frameborder="0" scrolling="no"></iframe>

Replace the "id" with the id of the makey that you want to embed. Lets say you want to embed this makey - http://www.makeystreet.com/makey/2976/, The makey id here is 2976. So the final embedded code will be 

<iframe src="//www.makeystreet.com/embed/makey/2976/" width="250" height="430" frameborder="0" scrolling="no"></iframe>

and the result that you would get is:

<iframe src="//www.makeystreet.com/embed/makey/2976/" width="250" height="430" frameborder="0" scrolling="no"></iframe>

Notice the "width" element and "height element". You can adjust them according your preference. Width of 250px and height of 430px is recommended. If you are using bootstrap, you can make this responsive by enclosing the embedded code in a column element and setting width ="100%" , leave the height as 430px. You could try this reference for setting height to 100% if necessary - http://stackoverflow.com/questions/20357992/iframe-in-bootstrap-will-not-take-up-100-of-height. Setting height to a 430 pixel is recommended. 

If you have any integration issues, let us know. We will be glad to help you out.