DIAGNOSIS That's classic worn-out dryer drum support rollers. They're plastic or nylon wheels with a bearing in the center that the heavy drum rides on. When the bearing seizes or the wheel wears flat, it creates metal-on-metal scraping.
FIX You'll need to replace the rollers. 1. Unplug the dryer. 2. Remove the front panel (usually a couple screws along the top edge, then slide it up and off). 3. You'll see the drum sitting on rollers at the front and rear. Manually spin each one. The bad one will be stiff, gritty, or won't spin freely. 4. Note how they're attached (often a central bolt), remove the old ones, and install the new ones. Reassemble in reverse order.
IF THAT DIDN'T WORK While you're in there, also check the drum glides (felt pads on the front rim) and the rear bearing (a central hub the drum shaft sits in). If these are worn or disintegrated, they can also cause noise and need replacement.
HEADS UP When handling the drum, be gentle. The metal is thin and can be bent. Also, take a photo with your phone before disconnecting any wiring harnesses so you know exactly how to plug them back in.