You Cannot

TL;DR: Metamagic requires that your next action be Cast a Spell, but to activate a Scroll you must use an Activate an Item activity that subordinates a Cast a Spell activity. Using Activate an Item is not the same as using Cast a Spell, so the metamagic feat's benefits are wasted.

The sidebar about In-Depth Action Rules states that:

Using an activity is not the same as using any of its subordinate actions. For example, the quickened condition you get from the haste spell lets you spend an extra action each turn to Stride or Strike, but you couldn’t use the extra action for an activity that includes a Stride or Strike. As another example, if you used an action that specified, “If the next action you use is a Strike,” an activity that includes a Strike wouldn’t count, because the next thing you are doing is starting an activity, not using the Strike basic action.

The metamagic trait states that:

Actions with the metamagic trait, usually from metamagic feats, tweak the properties of your spells. You must use a metamagic action directly before Casting the Spell you want to alter. If you use any action (including free actions and reactions) other than Cast a Spell directly after, you waste the benefits of the metamagic action. Any additional effects added by a metamagic action are part of the spell’s effect, not of the metamagic action itself.

Metamagic is just like the hypothetical action in the sidebar's example: activities that subordinate Cast a Spell don't work with it!

The Activate an Item activity states that:

You call forth the effect of an item by properly activating it. This is a special activity that takes a variable number of actions, as listed in the item's stat block. [...]

Activation Components

Each activation entry lists any components involved in the activation after the action icons or text, such as “ command.” The activation components, described below, add traits (listed in parentheses) and requirements to the activation. If you can't provide the components, you fail to Activate the Item.

• Command (auditory, concentrate)
• Envision (concentrate)
• Interact (manipulate)
• Cast a Spell

Activation Components An item's activate entry lists the components required to activate its abilities. Each component adds certain traits to the Activate an Item activity, and some components have special requirements. The components that appear in this book are listed below. [...]

If an item lists “Cast a Spell” after “Activate,” the activation requires you to use the Cast a Spell activity to Activate the Item. This happens when the item replicates a spell. You must have a spellcasting class feature to Activate an Item with this activation component. If the item can be used for a specific spell, the action icon for that spell is provided. If it's an item like a staff, which can be used for many spells, the icon is omitted, and you must refer to each spell to determine which actions you must spend to Activate the Item to cast it. In this case, Activate an Item gains all the traits from the relevant components of the Cast a Spell activity.

There's a lot here, because Activate an Item is basically a catch-all, but the bottom line is that when you are activating items you are using the Activate an Item activity. For some items like staves or scrolls, this activity includes (and therefore subordinates) the Cast a Spell activity.

Unlike other items, the scrolls have omitted the usage and activate entry from their stat block, but these entries are still found within the rules for Casting a Spell from a Scroll:

Casting a Spell from a scroll requires holding the scroll in one hand and activating it with a Cast a Spell activity using the normal number of actions for that spell.

To Cast a Spell from a scroll, the spell must appear on your spell list. Because you’re the one Casting the Spell, use your spell attack roll and spell DC. The spell also gains the appropriate trait for your tradition (arcane, divine, occult, or primal).

Also, note the difference with rules for Casting a Spell from a Staff, where an exception is made for metamagic feats to work with staves:

Use your spell attack roll and spell DC when Casting a Spell from a staff. The spell gains the appropriate trait for your magical tradition (arcane, divine, occult, or primal) and can be affected by any modifications you can normally make when casting spells, such as metamagic feats.