Many heuchera varieties produce flowers carried above the leaves on upright stems. Often these flowers are small and insignificant and have little appeal, although they are popular with pollinators, and simply distract attention from the appeal of the many foliage colors and patterns.
That is why it is often recommended that the flowers be snipped off when still in bud. It is important to snip them off carefully, below the level of the leaves, so that the remains of the stems are hidden.
Because the stems are slim and require careful cutting, you might find it easiest to use a pair of narrow-bladed garden snips, like this small pair by Vivosun on Amazon.
Some varieties, however, have larger and more colorful flowers and these should be left uncut.