The timing belt and balancer belt are cogged. They cannot squeal.

It's either an accessory drive belt/serpentine belt that's loose or
misadjusted. Or...

If the installer did not replace the timing belt tensioner, it could be
seizing, which can cause a horrendous noise. This is very bad.

Tighten accessory drive belt(s). Replace if cracked/glazed/packed with
gravel. If noise persists, a tensioner is squealing.

Apparently smearing talcum powder/baby powder on the friction surface
of the belt can cause it to grip enough to stop a squeal for a while,
so you can try that to see if the belt shuts up.

If fiddling with the belts does not stop the squeal, better get that
tensioner looked at. A failed tensioner will cause your timing belt to
jump. This can wreck your valves.

Check your "normal" belts by trying to move them at the point that is the
longest distance between pulley's.  If you can move them an inch or more,
then you need to have them tightened.  On the same belts, look at the sides
of them by twisting the belt.  If they are glazed, you might get away with
getting a can of spray-on belt dressing.  If they are cracked, I'd have them
replaced.  If none of these situations are present, you may need to go back
to where you had your timing belt replaced and have them check their work.