i wrote quiero tomar el autobus, without an accent. It didnt accept my answer
You know that could also mean literally taking the bus in english, right? To make it more specific you could say "i want to ride the bus.", Instead
The phrase I am most familiar with is 'catch the bus'.
Catch and take are the words most commonly used when wanting to travel (or ride) on public transport, but both words can have other meanings. However, context is the key.
Best not to get hung up about it, especially as Duo accepts both.