If a website is marked and blacklisted by Google, a visitor gets a distinct, full-screen alert blocking access to the respective site.
Unfortunately, the majority of blacklisted websites are, in reality, legitimate websites where hackers have inserted malicious content.
You can inspect specific links of your website with the help of https://transparencyreport.google.com/safe-browsing/search.
Try Scan and remove the malicious content from your site - You can use the Virus Scanner option in cPanel
Also register and verify your site in the https://search.google.com/search-console/about.