To add launch screen in Xcode:
1- First add your launch screen image in Xcode by going to Build Phases/ Copy Bundle Resources and your image by clicking on the plus button
2- Now add your launch image by going to LaunchScreen and clicking on the Plus button on the top right corner and searching ImageView
3- Now add your launch image by going to the Image View panel on the right side
4- Click on the bottom constraints section and make sure all values are 0
5- Go to the Image View panel on the right side and set Content Mode to Aspect Fill.