Overgrown neighbours tree is about to block daylight and view.

Hello, hope this email finds you well. I would like to report this issue and the tree grows really fast and I’m worried about loosing daylight in my property. A year ago the tree was twice shortly as it is now. Could please someone advise how can we resolve this problem. I don’t feel comfortable going downstairs to speak to them. I think they’re just tenants of the property below flat 46 Shaftesbury court. Many thanks for your help