The fighter's Action Surge feature (post errata mentioned in the 2019 Sage Advice Compendium) now states:
On your turn, you can take one additional action.
The Eldritch Knight fighter gets the Arcane Charge feature (PHB, p. 75), which states:
At 15th level, you gain the ability to teleport up to 30 feet to an unoccupied space you can see when you use your Action Surge. You can teleport before or after the additional action.
Are you allowed to take Action Surge's "additional" action, thus allowing you to use Arcane Charge, and then take your regular action?
If you have to use your normal action first, then your options are Action --> Teleport --> Action Surge and Action --> Action Surge --> Teleport. If you can use Action Surge first, this gives you the new option of Teleport --> Action Surge --> Action.