As long as the tiles are in good condition, flat, and there are no hollow or drummy tiles, then you can lay hybrid vinyl flooring directly over floor tiles. They are 100% waterproof and ideal for use in bathrooms and laundries.
It would be worth considering if the additional cost of priming, self-levelling, priming again, and the stick-on product itself would come close to using hybrid vinyl. Here's the installation guide for the stick-on vinyl, which takes you through the process to level tiles. - MitchellMc