If your goal is "Buy PTE Certificate", bear in mind that only official evaluation results count
https://pte-certificate-onlinesljl634.tearosediner.net/what-s-the-point-of-nobody-caring-about-pte-certificate-for-visa-purposes
If your objective is "Buy PTE Certificate", keep in mind that only official assessment outcomes count. Use practice tests, improve accuracy and timing, and make a validated Pearson PTE result through the examination.