Do you have really flat tiles or are the grout lines sticking out quite a bit? That's the real question before you get started. I tried putting it directly on some old smooth tiles at my mum's place last year, and honestly it held up for a few months before the clicks started making noise and the planks started lifting in places.
What saved me was that she agreed to let me put down a self-leveling underlayment (like Ardex or Ceresit) to smooth everything out - it's not complicated to lay, you just leave it to set for 24-48 hours before putting the vinyl down.
If your tiles are really even and without big bulging grout lines, maybe a thin isolation underlayment like cork or foam would work, but honestly the self-leveling compound is safer and doesn't cost a fortune in 2026.