I just tried it on Parrot 6.0 and sudo nano ~/.bashrc worked for me. Assuming you’re using bash and not zsh as I usually am (it would be sudo nano ~/.zshrc in that case) and you only want it on your users profile .
I used " banner EXAMPLE BANNER " in my bash script.
I believe sudo nano /etc/bash.bashrc should work to but take effect system-wide.
Thank you
Also have you had any success on getting custom pointers to run ive downloaded and installed different options from gnome-outlook.org but no luck installing them