Generally not until it is paid and irrevocably committed. Capital counts when it is at risk of partial or total loss, and a contingent future payment is not.
Count the dollars that could actually be lost
Hypothetical example: The investment test looks at capital irrevocably committed to the enterprise and subject to loss if the business fails. An earn-out fails both halves at the point of application: the buyer has not parted with the money, and if the business underperforms the buyer will simply never pay it. Presenting the full headline purchase price as the investment invites a finding that the file overstates its own case, which colours everything else in it.
The better approach is arithmetic honesty. Show the cash paid at closing, the non-refundable deposits already expended, the equipment and inventory purchased, the lease commitments entered, and any loan proceeds for which the investor is personally liable and which are not secured by the assets of the business itself. If that committed figure is too small to be substantial against the cost of an established business of this type, the answer is to restructure the deal before signing, not to argue the earn-out upward.