How to integrate your site to another via iframe?

Question

Mobile development

There is a working web application on your domain, you need to give everyone the opportunity to integrate it through an iframe into your site (just like applications in social networks, they just add everything to their site).

Tell me how it's done right? How to link a client (another website) to a user in a database. That is, in fact, another site is, as it were, another user in my site.

Answer 1

in the link to the iframe indicate the identifier of the site - partner
For example

<iframe src="http://example.com/?client_id=1"></iframe>