When I first started working, I had difficulty estimating time. I feel quite afraid that the estimate is lack of time. It made me feel quite pressured. Sometimes I have to work overtime, sometimes I have to ask the help of my colleagues. After a few times, during the sprint review meetings, I asked that question and got a few suggestions. When I receive a product request, I will break it down into small tasks, prioritize and find a few solutions for those small tasks.
And if possible, I will consult the leader of that solution. finally give a time estimate.