The glutes are the biggest muscle group in the body and are roughly equal parts fast and slow-twitch muscle fibers. That said, increasing the weight is often a great way to progress glute strength and muscle hypertrophy. However, it is not the only way.
If you are limited by the amount of weight you have access to, you can also incorporate tempos, increased ranges of motion (hip flexion), and short rest periods to increase metabolite build-up and muscular fatigue. You can also play around with exercise order or pair these with more compound exercises like squats to further increase muscle breakdown.