No it's not possible. They need credentials to run the script. There's no way to let them connect using the credentials, while absolutely hiding the credentials way from them.
See also https://winscp.net/eng/docs/guide_protecting_credentials_for_automation

Hello

I am having a hard time searching for this.
I am trying to create a script which i can send to people along with the portable version of the program. The problem is i don't want the people who are running the script to be able to connect to my server for anything else than the script.
Is there a way to do this so that the user cannot connect to the server?