hello house, i was directed to a tls website after paying for my visa, now am required to pay for anotthr fee,but where am having issues is on my GWF number, i really dont get it as my own gwf number starts with ukvi, plz quick reponse will be appreciated

Plz and plz I need a quick response to my questions..... I want to apply for a visitor visa in the UK, my elder brother is inviting me over and I want to apply for it this week, he is the one sponsoring everything so my question is.....is my statement of account really important? As he is the one sponsoring my stay. I have close to nothing in my account....am single with a menial teaching job, plz I need a quick and sincere response