After installation of Haskell: Haskell works, but isn’t attainable in terminal

I installed Haskell for the use of TidalCycles on Mac / 10.14.6
TidalCycles works fine, so Haskell should to work too.
However, after entering ‘ghci’ in the terminal, the following message appears

-bash: ghci: command not found

Do I have to set a correct path (e.g. .bashrc)? And if so, where to?

Thanks for every help!