Automatic link in the text of the new post

Hi everybody,

I need to automate the creation of a link to another site so that when a unregistered user makes a new post that will contain http, that post will automatically appear as a link and not as plain text.
For example, after inserting this text (“www.xxx.com”), it will automatically be created as a link to the given page: xxx.com. I tried plugins Frontend Post Submission Manager Lite , User Submitted Posts but failed with theme. can you please advise me how to do it?