Problems to install QT Designer - Linuxcnc 2.9.3

Hi,
wanted to install QT designer as described in pdf-documentation (section 12.5.4.2 on page 1073)
It doesn`t work.
 
Please help me. 
Thanks

What linux distribution are you using?
What error messages did you get?

I installed via USB:
www.linuxcnc.org/iso/linuxcnc_2.9.3-amd64.hybrid.iso
linux distribution Debian 12

Following errors:
qttools5-dev-tools not available
qttools5-dev can`t be found
libpython3-dev can`t be found

I found an issue in my file source.list. This is now correct.
Installed QT Designer with success.

2 issues I have to fix due to:

How can I add a symbolic link and create the plugins/python folder in detail, so that qt designer can find qtvcp_plugin.py?
Tried to create python folder with command mkdir, but it isn`t possible in folder /designer to get:
’/usr/lib/x86_64-linux-gnu/qt5/plugins/designer/python’
 

Fixed with thread:
forum.linuxcnc.org/qtvcp/38414-installing-qtvcp