cd in shell not working, WSL Ubuntu [duplicate]

I am using WSL/Ubuntu on Windows 10. I want to go to /mnt/c. Typing cd /mnt/c is working. But when I enter the command into a shell script, it is not.

1. I added the line: cd /mnt/c to a shell script

2. I used chmod +x. When executing the script, the position in the shell did not change

3. I added the command ls

   ls /mnt/c was executed
   

How can I move to /mnt/c using a script?

thansk Harald