Weird pop-ups after clicking anywhere on my homepage

Hi. Yesterday I’ve noticed that when I click anywhere on me website’s homepage, weird pop-up with ads appears. I haven’t put it. I only have 2 Adsense ads, but I’ve put it into theme’s code by myself – no ads plugins used. I don’t want that pop-up. I’ve checked the source page, but I haven’t found any suspicious code. I thought it is a problem on my main website, but today I opened my second WordPress website and the popup also appeared. I also have a MyBB forum, but it’s free form that spam. Can anyone help me?

My main website: https://bowshrine.com/
My second website: https://soundtrackstream.com/