Making a selfie video with the iPhone

Hello,
I'm able to take pictures of me with my face centered. But I always fail when I try to film a video by using the front camera on my iPhone XS. Yes, my face is visible in the video but I cannot bring it into the middle. It seems to be incredibly hard to hold it in the right position.
Are there any tricks or filters or whatever to make this process a bit easier? I'm using the build-in camera app.
Thank you for your help!