cronjob get permission error for folders

I tried to write a script to clean up some folders e.g. ~/Downloads.

If I run the script in Terminal it works. If I add the script to a "crontab -e" it doesn't.

I wrote a test script to get some information about the environment:

test_cron.sh:

#!/bin/sh

echo "User $(whoami) in $SHELL"

ls ~/Downloads

crontab -e:

17 21 * * * ~/.services/test_cron.sh > ~/.services/cron_test.log 2>&1

cron_test.log:

User tim in /bin/sh

ls: /Users/tim/Downloads: Operation not permitted

Privacy & Security Settings:

I used MacOS 15.1.1

I would be grateful for any help.