We are offering 2,857,143 shares of our ClassA common stock at a price of $2.10 per share to an institutional investor pursuant to this prospectus supplement and theaccompanying prospectus. In a concurrent private placement, we are also offering to such institutional investor common stock purchase warrants to purchase an aggregate of up to 1,428,571 sharesof our ClassA common stock. The purchase warrants have an exercise price of $2.30 per share, are initially exercisable six months from the date of issuance, and willexpire four years following the initial exercise date. The purchase warrants and the shares of our ClassA common stock issuable upon the exercise thereof are not beingregistered under the Securities Act of 1933, as amended, or offered pursuant to this prospectus supplement and the accompanying base prospectus, and are instead beingoffered pursuant to an exemption provided in Section4(a)(2) of the Securities Act of 1933, as amended. Our ClassA common stock is listed on the New York Stock Exchange under the symbol “OPAD.” On July23, 2025 the last reported sale price of our ClassA common following the commencement of sales in this offering and we will deliver all securities to be issued in connection with this offering delivery versus payment/receiptversus payment upon receipt of investor funds received by us. Accordingly, neither we nor the placement agent have made any arrangements to place investor funds in an escrow account or trust account since the placement agent will not receive investor funds in connection with the sale of the securities offered hereunder.We engaged A.G.P./Alliance Global Partners to act as our sole placement agent in connection with this offering. The placement agent is not purchasing the securitiesoffered by us in this offering and is not required to arrange the purchase or sale of any specific number or dollar amount of securities, but will use its reasonable bestefforts to arrange for the sale of the securities offered hereby. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if thisprospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.Per Share of ClassACommonStockand AccompanyingPurchase Warrant $1.953(1)Represents a cash fee equal to 7.0% of the aggregate purchase price paid by the investor in this offering. In addition, we have agreed to reimburse certain expenses 16,688,914 shares are held bynon-affiliates,and a per share price of $3.11, based on the last sale price of our common stock on July21, 2025, a date that is within 60days of the date of this prospectus supplement.One-thirdof our public float, calculated in accordance with General Instruction I.B.6 of FormS-3,is equal toapproximately $17,127,832. During the 12 calendar months prior to and including the date of this prospectus supplement, we have not sold any securities pursuant to of our public float in any12-monthperiod so long as our public float remains below $75.0million pursuant to General Instruction I.B.6 of FormS-3.Delivery of the shares of ClassA common stock is expected to be made on or about July25, 2025. Prospectus SupplementABOUT THIS PROSPECTUS PROSPECTUS SUPPLEMENT SUMMARYTHE OFFERINGRISK FACTORSUSE OF PROCEEDSDESCRIPTION OF CLASS A COMMON STOCKPLAN OF DISTRIBUTION WHERE YOU CAN FIND MORE INFORMATION; INCORPORATION BY REFERENCE DESCRIPTION OF DEPOSITARY SHARESDESCRIPTION OF WARRANTS to this offering. If the information contained or incorporated by reference in this prospectus supplement differs or varies from the information containedin the accompanying prospectus or in any document incorporated by reference that was filed with the Securities and Exchange Commission, or the SEC, before the date of this prospectus supplement, you should rely on the information set forth in this prospectus supplement. In general, when we refer tothe prospectus, we are referring to both the prospectus supplement and the accompanying prospectus combined. You should rely only on the information contained or incorporated by reference in this prospectus supplement, the accompanying prospectus and in anyfree writing prospectus we may provide to you in connection with this offering. Neither we nor the placement agent have authorized any other person toprovide you with any information that is different. If anyone provides you with different or inconsistent information, you should not rely on it. We areoffering to sell, and seeking offers to buy, our securities only in jurisdictions where offers and sales are permitted. The distribution of this prospectussupplement and the offering of the securities in certain jurisdictions may be restricted by law. Persons outside the United States who come intopossession of this prospectus supplement must inform themselves about, and observe any restrictions relating to, the offering of the securities and thedistribution of




