Can a sorcerer use metamagic when casting a spell via a spell scroll?
If the spell is on your class’s spell list, you can read the scroll and cast its spell without providing any material Components. Casting the spell by reading the scroll requires the spell’s normal Casting Time. If the spell is on your class’s spell list but of a higher level than you can normally cast, you must make an ability check using your Spellcasting ability to determine whether you cast it successfully.
So, clearly, you are casting the spell from its scroll.
Reading Metamagic options, you have only 2 conditions:
Almost all options: When you cast a spell ...
Empowered Spell: When you roll damage for a spell...
So yes, you can use your MetaMagic features when casting a spell from a scroll.
If a magic item's description says you cast a spell from it, you can use Metamagic on the spell.