Undertone pop up - how can i get rid?

scooterb
scooterb Posts: 90
Hi , does anyone else keep getting the annoying pop up from Undertone?

I have tried to unsubscribe using their opt-out option but it tells me I was unsuccessful - here

Undertone OBA Opt-Out Results
Result
Legend You have successfully opted out from Undertone OBA Ads. You will continue
to receive ads from Undertone that do not use OBA.
Your opt-out attempt was not successful.
In order for you to successfully opt-out, your browser must be set to accept
3rd party cookies.

Can anyone help me stop these annoying pop up adverts please?
Im not sure what cookies are or do ?
Thanks scott.