Enough... Is Never Enough

The markets panel can be opened from the options in the top-right. You'll see options for buying/selling metal, crystal, and exotics - but only once your empire is advanced enough to be connected to other factions that want to trade the materials.

Sell lots of crystal to pop this.

NB it is not yet clear whether this has to be in a single match - but mid-late game in any medium or larger match you'll likely have more than enough crystal left to grind this out in a single match.

Then see Never Gamble With a Telepath. to buy it all back...

This is soft-missable as in late-game if the factions you can trade with have been destroyed then you're no longer able to trade and get this.