I've already canceled my account but the website is still indexed

If your website has been canceled it is normal that it takes time to remove it from search engines.
Just as it takes some time for a website to be indexed by the search engines, the reverse is likewise a process that takes time.

The process of removing a page from results is automatic and depends on search engines and not on our platform.

However, this process can be accelerated depending on the search engines.
For Google, see this link.
For Bing, see this link.