Up to $100,000,000

Class A Common Stock

We have entered into a sales agreement with Lucid Capital Markets, LLC (the "Agent"), relating to the sale of shares of our Class A Common Stock, $0.0001 par value per share, offered by this prospectus supplement and the accompanying prospectus. In accordance with the terms of the sales agreement, under this prospectus supplement we may offer and sell shares of our Class A Common Stock having an aggregate offering price of up to $100,000,000 from time to time through the Agent.

Our Class A Common Stock is listed on The NYSE American LLC ("NYSE American") under the symbol "FLYX." On March 11, 2026, the last reported sale price of our Class A Common Stock on the NYSE American was $2.41 per share.

Sales of our Class A Common Stock, if any, under this prospectus supplement will be made by any method permitted that is deemed an "at the market offering" as defined in Rule 415(a)(4) under the Securities Act of 1933, as amended, or the Securities Act. The Agent is not required to sell any specific amount, but will act as our sales agent using commercially reasonable efforts consistent with its normal trading and sales practices on mutually agreed terms between the Agent and us. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.

Under the terms of the sales agreement, we also may sell shares to the Agent as principal for its own accounts. If we sell shares to the Agent as principal, we will enter into a separate terms agreement with the Agent setting forth the terms of such transaction.

The Agent will be entitled to compensation equal to 2.5% of the gross sales price of the shares of our Class A Common Stock sold by them pursuant to the sales agreement. See "Plan of Distribution" beginning on page S-12 for additional information regarding the compensation to be paid to the Agent. In connection with the sale of the Class A Common Stock on our behalf, the Agent may be deemed to be an "underwriter" within the meaning of the Securities Act and the compensation of the Agent may be deemed to be underwriting commissions or discounts. We have also agreed to provide indemnification and contribution to the Agent with respect to certain liabilities, including liabilities under the Securities Act. See "Plan of Distribution" beginning on page S-12 regarding the compensation to be paid to the Agent.