Avast antivirus and my website

Hi there i have installed avast antivire from a similer website like avast but after installing i have getting issues like auto prompt open and the major issue with my website whenere i open my website it always give me option of spanish it happen after installing avast antivirus what is the issue?

You should always install Avast direct from the Avast website or from an authorised reseller only, not a “similar” website that could be a scam.
Which Avast product was it and where did you actualy get it from?