I GET A POP-UP FROM GOOGLE WHEN I TRY TO GET EMAIL USING THUNDERBIRD. IT SAYS “SIGN IN TO CONTINUE TO MOZILL A THUNDERBIRD EMAIL” UNDER THAT IS “EMAIL OR PHONE

I GET A POP-UP FROM GOOGLE WHEN I TRY TO GET EMAIL USING THUNDERBIRD. IT SAYS “SIGN IN TO CONTINUE TO MOZILL A THUNDERBIRD EMAIL” UNDER THAT IS “EMAIL OR PHONE” UNDER THAT IS MY EMAIL ADDRESS. UNDER THAT IS WHAT APPEARS TO BE A LINK TITLED “MORE OPTIONS” AND NEXT TO THAT IS BUTTON TITLED "NEXT” WHEN I CLICK ON THE LINK OR THE BUTTON NOTHING HAPPENS. WHY AM I GETTING THIS POP-UP. IT IS PREVENTING ME FROM GETTING MY EMAIL.