The Git command to add all modified or deleted files to the staging area is:

git add -u

The -u flag tells Git to update the index with all changes to tracked files, including modifications and deletions. This command will not add any new files that are not currently tracked by Git.

Alternatively, you can use the following command to add all modified, deleted, and untracked files to the staging area:

git add -A

–> The -A flag tells Git to add all changes to tracked files and all untracked files to the staging area. This command is useful if you have added new files that are not currently tracked by Git, and you want to add them to the staging area along with any modifications or deletions.

It’s important to note that adding files to the staging area is just the first step in committing changes to your Git repository. After adding files to the staging area, you will need to use the git commit command to create a new commit with your changes.