If your goal is "Buy PTE Certificate", bear in mind that only official examination outcomes count
https://www.mediafire.com/file/5ba25zt4ql2oz3s/pdf-3715-77765.pdf/file
If your objective is "Buy PTE Certificate", keep in mind that just official examination results count. Use practice tests, enhance accuracy and timing, and make a verified Pearson PTE result through the exam.