clobber

I’m having trouble with a Perforce error message that says “can’t clobber writable file”. I’m not sure what that means or how to fix it. I tried searching online for solutions, but the ones I found didn’t work for me.
Here’s the code that’s causing the problem:

p4 edit file.txt
echo "Hello World" > file.txt
p4 submit -c "Added Hello World to file.txt"

After running this code, I get the error message “can’t clobber writable file”. I’m not sure what it means. I thought maybe it was a permissions issue, but I checked and I have write permissions for the file. I also tried running the code as an administrator, but that didn’t work either.
I’m not sure what else to try. Can anyone help me figure out why I’m getting this error message and how to fix it?