There are a few steps to follow:
First: remove unfamiliar extensions from your Google Chrome. Open a new tab and then click the 3 dots in the upper right hand corner. Scroll down to More Tools and then click Extensions. This will open a new page listing your extensions. Underneath any extensions you do not use or do not recognize, click remove.
Second: reset your Chrome Settings. Click on the 3 dots in the upper right hand corner and scroll down to Settings, click into it, which will open a new tab. Go all the way to the bottom and click on Advanced, then go all the way to the bottom again and click Restore Settings To Their Original Default.
Third: ensure that pop ups are disabled. Click the 3 dots in the upper right hand corner and scroll down to Settings. Once the new page opens click Advanced and go down to the Privacy and Security labeled section. Click on Site Settings and then go down to Pop Ups and ensure that it says they are blocked. If it does not say blocked click on the Pop Ups setting and to open settings, there should be a toggle that if you click will go from blue to grey and they should say blocked. Then close out of this tab.