Find a broker/platform in your country that lets you trade in the stock market they are listing on (if UK then IG and Hargreaves Lansdown are good), join, fill

Find a broker/platform in your country that lets you trade in the stock market they are listing on (if UK then IG and Hargreaves Lansdown are good), join, fill out the W-8BEN so you are able to buy US stock through the platform (they usually make this a 2 minute job) and then place an order when it’s live. You’ll be paying more than the true IPO price as the bank etc get preferential rates I believe but it’s as good as you’ll get