On computer when page froze and I got message in middle of screen and voice that my Mac computer was locked and my "PC" had Trojan virus

Nice to meet you, *****!
Could you tell me, please, can you remove that inscription about the virus and use your Mac? Or is the page totally frozen?

If your computer will work properly, it means that it was a scam, like the fake message, Ignore it and get out of that website. The idea is to scare you into buying a service or an app to "protect you" when there is nothing wrong with your device
The real one has an "apple.com" domain
Do you remember, if it was in that notification?

Could you, please, make a photo of this message and send it to me
To attach pictures to our chat, you need to press the paper clip button in the lower right corner of the chat window. Then you have either to choose an image on your device or take a photo right away. Then confirm sending.

Don`t call this number, please, it is still a high risk that it might be a scam
*****, how is it going? Could you send me a photo of what you see, please?

Yes, sure, I`m here
On what stage are you now?

Are you chatting with me now with your phone?

Do you have an opportunity to make a photo with your Kindle?

Could you specify, please, what is this link?

Okay, I see, thank you for the information

And it doesn`t have the "apple.com" domain, right?
No worries, we can do it without a photo

*****, I`ve made some research
*****.app is a sort of malware that infuses into your PC, and after that modifies the browser search engine configurations in your internet browser to one which it is paid for. It likewise makes different unwanted modifications that might lead to personal data leakages, in addition to other malware penetration
So it is a 100% scam, don`t do anything with it, just close the page where it has appeared

And, please, be careful with this scam-world
Install legitimate anti-virus and firewall software and make sure you keep it up to date. Don't click on links or attachments in an unsolicited email, even to unsubscribe. Go to the organization's own website. Don't reply to scam emails even to say no – this lets the scammer know the account is active.
Perfect!
I’m glad I was able to get that sorted out for you. Is there anything else I can assist you with today?

As for me, the best anti-virus for Mac is TotalAV
You can install it by this link https://www.totalav.com/