BEIJING             -             If you can make smartphone apps, Chinese tech giant Huawei wants you. The No. 2 global smartphone brand is struggling to hold onto its market after Washington accused Huawei of being a security risk and blocked access to U.S. components and technology. That includes YouTube and other popular Google “core apps” customers expect on new phones. They will be missing from the global rollout of Huawei’s next model, the P40, due out in March, replaced by its own music, payment and other apps. Huawei Technologies Ltd., along with every other smartphone brand except Apple Inc., relies on Google’s Android operating system. So it’s scouring the world for replacements. At events for developers from New Delhi to Warsaw to Sao Paulo, Huawei is promising cash rewards if they meet a deadline Friday to get apps onto its online store. The company says it will invest $1.5 billion in app development. It faces an expensive, uphill struggle to create alternatives to the Google-centered world of music, navigation and other apps, according to industry experts. Others including Nokia and Microsoft have tried and failed to create their own mobile ecosystems. Creating “diverse apps” is a “really challenging task to Huawei,” said chairmanGuo Ping in videotaped comments released by the company.