Hi You may wish to consider using an add-on to block these type of adverts. An example of such an add-on in [https://addons.mozilla.org/en-us/android/addon/ublock-origin/ uBlock Origin]. I recommend you follow this [https://support.mozilla.org/en-US/kb/find-and-install-add-ons-firefox-android guide] that will walk you through how to install the add-on. I hope this helps, but if not, please come back here and we can look into a different solution for you.