Pop Up message says "Finder.app" wants to access & control "Safari.app". Click "OK" or "Don't Allow" ??

I was reading an article about hidden Trackers in emails and I saw mention of an app called "Ugly Email" which I googled. I read a few entries and viewed one video about "Ugly Email". Whilst still on the page listing the results for the google search, a Pop Up appeared stating:- 

"Finder.app" wants access to control "Safari.app". Allowing control will provide access to documents and data in "Safari.app", and to perform actions within that app. DON'T ALLOW  or  OK.    These were the available options. (There is a logo within the Pop Up which has similarities to some of Apple's logos:- an icon of a house with a round gear symbol attached to the bottom right of the house.)

I took neither option . Instead I shut down the google tab showing the results of the search for "Ugly Email". Then I shut down the iMac, removed all attached cables including the power cable at the wall. Then I switched the iMac back on. Shortly after, the Pop Up reappeared and is still siting on the front of my desktop.

I have never seen this Pop Up or anything similar before. I have never been asked to give access of the kind this Pop Up in requesting. It appeared  when I was looking through articles and viewing a video relating to hidden Trackers in emails, as described above.

I would appreciate advice as to what I to do. Should I click on one of "Don't Allow" or  "OK" ? And if so which one.  Or is there some other way of getting rid of this persistent Pop Up ?  Is it malware or legitimate ?