I want to enter a Ddim7, but I found that only Ddim can be entered.
how to solve this problem?

You might try this:
Options/preferences/display and click on treat dem chord........

You may find the Ddim is what you want as BiaB includes the 7.
The half-diminished is written a Dm7b5.

thanks!

Not necessarily. If you look at my response you will see that you can type nDim and get the half-diminished. I know that this works in MIDI but you may get different results in RTs as you will get what was recorded regardless of what you want/typed.

According to your screenshot prompt,
I checked all of them, and now everything is normal. thank you very much!

I'm glad that I could help.

You should label this thread as resolved.