In SharePoint, content is automatically crawled based on a defined crawl schedule. It is possible if the link is in a document or on a page, as the link will be treated as text strings while searching.
Make sure content can be found
A similar post:
How to search for a specific link in SharePoint Online
I can't yet reply or comment (or even vote?) on other's posts, but Dave Schmidt's reply is more helpful generally. For folks using a communication site, the "Return to Classic Sharepoint" doesn't appear because the Quicklaunch is a top bar and not the side nav of the typical site. If you have a commmunication site, Dave Schmidt's answer here is ...
I'm not sure if this is the correct fixed, but i came across an article to add exception for port 808 in the Windows Firewall between the SP servers (for me WFE and Search server) and user is reporting the result are showing up.