ChatGPT macOS app: shortcut to focus the current chat composer?

I use the ChatGPT macOS app alongside another app and repeat this loop constantly: copy text, Command+Tab back to ChatGPT, then paste or type into the same ongoing conversation.

After I’ve scrolled through the chat, focus is no longer in the composer. Command+Tab brings the app forward, but I can’t find a dependable keyboard shortcut that puts the cursor straight back into the message box. Having to reach for the mouse or trackpad and click it several times per minute is surprisingly disruptive.

Option+Space / Quick Chat and Command+N don’t solve this, because both move away from the existing conversation I’m trying to continue.

Is there an undocumented shortcut, a macOS accessibility command, or another reliable keyboard-only workaround for focusing the composer in the current chat?