Hello @mchin ,
After contacting MacPorts support, we have a solution for Python 3.13 (or Python3.12 as well for you).
You can test it with the following instructions:
sudo port install tk +x11 # not needed in your case
Then rebuild py313-tkinter from source
sudo port -ns upgrade --force py313-tkinter
Or, if you haven’t installed the port yet, use:
sudo port -ns install py313-tkinter
Before testing, remember to select the proper Python version 
sudo port select --set python3 python313
Let me know if this works for you as well.
Cheers, Luigi