Stand with a staggered / split stance and neutral spine, and the front leg slightly bent.
Begin hinging at the hips, keeping a neutral spine, and feel your hamstrings engage.
Allow your front knee to bend further to allow you deeper into the hinge. Continuing until you reach the end of your hamstring flexibility. Do not try to go lower by flexing the lumbar spine, your back should remain neutral throughout the movement.
Push through your heel to drive your hips through. Fully extending at the top, squeezing the glutes. Repeat for repetitions and switch sides.
Hamstrings should remain under tension throughout, if you lose engagement it's likely your back is rounding.
(Note : You can place the edges of your hands into the crease of your hips for feedback, making sure your initiate the movement by hinging)