Can I connect my amp to Scarlett 2i2?
You can, in fact, plug directly in using a 1/4" jack - either directly from the guitar or from your amp or pedal's line out.
Can you plug a Focusrite into an amp?
In Focusrite Control, this setting is defined on the Device Settings page. Connect this output to your re-amp box to take the signal from 'balanced line' to 'unbalanced instrument' level (the level your amplifier is designed for), then connect the output of the re-amp box to your guitar amplifier.