hi all,
i managed to make the changes, i had two mistakes:
i had to clear the kimai cache via terminal (it is in the kimai docs)
https://www.kimai.org/documentation/configurations.html
when trying to clear, so the effects take place, i got an error. apparently you cannot use tabs as indentation, so my local.yaml was not readable anyway
after using spaces and clearing successfully the cache, every worked 🙂
thanks for the help!