Unable to activate a new environment in Windows

When I tried activating a development environment this is what happened:

(base) PS C:\Users\David\anaconda3> _conda activate devapps

CommandNotFoundError: Your shell has not been properly configured to use ‘conda activate’.

I looked for a solution, but I don’t really understand the nature of the error and nothing I’ve tried has worked. So I’m currently unable to proceed with anything.