Fix and build my app

Note this is 2 app 1st app : add auth use third party API for my app API means API of app marketplace, deploy frontend, backend and domain, 2nd app: Build me a web messaging all features included use sdk and use third party API for my app means API of App marketplace, both needs API, ill Explain the API low budget dev under $200 if you can do this 2 apps for $200 we can start. Note we need to start it this week. thanks