No SFreq/RFreq columns

Hello,
Thank you for your extension.
I installed it, then restarted my computer, but I cannot add SFreq/RFreq column:
<img width="743" height="789" alt="Image" src="https://github.com/user-attachments/assets/71a64d80-149b-4387-b313-fd4b60b40807" />

Where can I add those columns ?

## Information
Sender Frequency 3.1.1
Thunderbird 140.2.1esr (64-bit)
OS Windows 11