Hello devs ...So I applied to some marketing agency in my locality as a front end developer with specialization in react. I was called for an interview and then I was told they're currently need someone with mobile experience specifically flutter to work on their upcoming apps.
My interviewer told me he was very much impressed with github repo page but he would like me to join them but will learn flutter since that was going to be their main stack for mobile apps. I had to start learning right away and I could tell i was making progress with it. Fast forward to three weeks of my stay , he asked me whether I could build a lock screen . The purpose of this is to display custom ads on them to customers. I told them I could do it but I will take some time. I know somehow I could do it but I just don't know how to go about this, to the execution.
I feel like a fraud and sooner or later I will tagged as incompetent to serve as a developer in their company.
Note: this happens to be my first developer role as I have never had any professional experience before and there is no other developer to look up to. It's all by myself.
Please I need some advice. What should I do?