BTEC papers are restricted — Pearson only releases some externally and locks the rest behind a teacher login. PMT doesn't host BTEC either. The best places to find extra material:

Pearson's own qualifications page hosts recent externally assessed task papers and mark schemes once they're released. Save My Exams has some BTEC Sport revision notes. Beyond that, ask your teacher for any secure mock papers they have access to — Pearson distributes additional assessments to centres that aren't publicly listed.