I found it here
C:\Program Files\Eclipse Adoptium\jdk-126.96.36.199-hotspot
To run Mendix, there are some system requirements:
Normally, if you don't have any JDK installed, it happens automatically on Mendix installation. It's possible that this failed for some reason.
If necessary, you can either manually install or manually select the install location in Edit > Preferences to make sure you can run your application.
Great thank you, it's working again.
I had exactly the same issue while working on Mendix version 9.6.7 ; however, I found the bin folder in C:\Program Files\Eclipse Adoptium\jdk-188.8.131.52-hotspot. Now it is working fine!.
Thank you all for your valuable comments.