Department manager offer me to transit to new position in a new unit
I have been working in a financial workplace for 3 years now starting from software developer to senior software developer. I started when my Development Application Unit (DAD) just start. It means me and my manager is the first 2 person. Now we have more than 10 members. Today, department manager ask me for a private short meeting and he offer a suggest about position moving to Research and Development which he said a new brainstorming unit in his proposal he just discussed and got approved from CEO. He says based on my education background and job performance, I should consider. Also, we are in focus more on revamp our digital products. In the new Unit, I will be the only one for now. I know it will be more responsibility point to me as the structure is in thinking and I am direct under him. Instead of my current unit, I will research, present and demo to DAD and support team to adapt the change. It is like a supervisor unit of every digital product here, doing research in the range from security to new feature to make sure everything update-to-date, safe and smoothly. I feel pressure for now as I am unsure what to do. As software developer, mostly we are under clear procedures/tasks. Now, it is about moving to something unclear, more tasks and responsibility. I also don't know if it is a giving opportunities to grow and the way to toss me out. I have a short time to make a decision. But for now, I feel not ready, not enough ability and feel 80% reject this offer. I afraid there will be more consequent in all cases. Need your advices.

I have been working in a financial workplace for 3 years now starting from software developer to senior software developer. I started when my Development Application Unit (DAD) just start. It means me and my manager is the first 2 person. Now we have more than 10 members.
Today, department manager ask me for a private short meeting and he offer a suggest about position moving to Research and Development which he said a new brainstorming unit in his proposal he just discussed and got approved from CEO.
He says based on my education background and job performance, I should consider. Also, we are in focus more on revamp our digital products.
In the new Unit, I will be the only one for now. I know it will be more responsibility point to me as the structure is in thinking and I am direct under him. Instead of my current unit, I will research, present and demo to DAD and support team to adapt the change. It is like a supervisor unit of every digital product here, doing research in the range from security to new feature to make sure everything update-to-date, safe and smoothly.
I feel pressure for now as I am unsure what to do. As software developer, mostly we are under clear procedures/tasks. Now, it is about moving to something unclear, more tasks and responsibility.
I also don't know if it is a giving opportunities to grow and the way to toss me out. I have a short time to make a decision. But for now, I feel not ready, not enough ability and feel 80% reject this offer. I afraid there will be more consequent in all cases. Need your advices.