New Millennium Bank Customer Service Issues

I am currently residing in Lagos, Portugal and recently opened a personal savings account with Millennium Bank. I am trying to make a payment to a Portuguese insurance company through Millennium Bank's online platform. Unfortunately, I am experiencing issues where the payment details I enter keep disappearing when I try to move to the next field. I have attempted to use a different computer but encountered the same problem. I am seeking guidance on how to navigate the payment process on Millennium Bank's website. Thank you for any assistance. I also want to express my frustration with Millennium Bank for not providing online customer support, which I find quite inconvenient.