Nagging notification

This seems to be associated with one football.com - is that a dodgy football streaming site?

If so, remove any associated apps that might be using it. (Does clicking on details show you what app that might be?)

See:

https://www.threatcrowd.org/domain.php?domain=feedmonster.iliga.de

Have a look in settings, calendar, accounts.

Is there anything in there related to one-football?